BackupPC Introduction
This documentation describes BackupPC version 3.1.0, released on 25 Nov
2007.
Overview
BackupPC is a high-performance, enterprise-grade system for backing up
Unix, Linux, WinXX, and MacOSX PCs, desktops and laptops to a server's
disk. BackupPC is highly configurable and easy to install and
maintain.
Given the ever decreasing cost of disks and raid systems, it is now
practical and cost effective to backup a large number of machines onto
a server's local disk or network storage. For some sites this might be
the complete backup solution. For other sites additional permanent
archives could be created by periodically backing up the server to
tape.
Features include:
o A clever pooling scheme minimizes disk storage and disk I/O.
Identical files across multiple backups of the same or different PC
are stored only once (using hard links), resulting in substantial
savings in disk storage and disk writes.
o Optional compression provides additional reductions in storage
(around 40%). The CPU impact of compression is low since only new
files (those not already in the pool) need to be compressed.
o A powerful http/cgi user interface allows administrators to view
the current status, edit configuration, add/delete hosts, view log
files, and allows users to initiate and cancel backups and browse
and restore files from backups.
o The http/cgi user interface has internationalization (i18n)
support, currently providing English, French, German, Spanish,
Italian, Dutch and Portuguese-Brazilian.
o No client-side software is needed. On WinXX the standard smb
protocol is used to extract backup data. On linux, unix or MacOSX
clients, rsync or tar (over ssh/rsh/nfs) is used to extract backup
data. Alternatively, rsync can also be used on WinXX (using
cygwin), and Samba could be installed on the linux or unix client
to provide smb shares).
o Flexible restore options. Single files can be downloaded from any
backup directly from the CGI interface. Zip or Tar archives for
selected files or directories from any backup can also be
downloaded from the CGI interface. Finally, direct restore to the
client machine (using smb or tar) for selected files or directories
is also supported from the CGI interface.
o BackupPC supports mobile environments where laptops are only
intermittently connected to the network and have dynamic IP
addresses (DHCP). Configuration settings allow machines connected
via slower WAN connections (eg: dial up, DSL, cable) to not be
backed up, even if they use the same fixed or dynamic IP address as
when they are connected directly to the LAN.
o Flexible configuration parameters allow multiple backups to be
performed in parallel, specification of which shares to backup,
which directories to backup or not backup, various schedules for
full and incremental backups, schedules for email reminders to
users and so on. Configuration parameters can be set system-wide
or also on a per-PC basis.
o Users are sent periodic email reminders if their PC has not
recently been backed up. Email content, timing and policies are
configurable.
o BackupPC is Open Source software hosted by SourceForge.
Backup basics
Full Backup
A full backup is a complete backup of a share. BackupPC can be
configured to do a full backup at a regular interval (typically
weekly). BackupPC can be configured to keep a certain number of
full backups. Exponential expiry is also supported, allowing full
backups with various vintages to be kept (for example, a settable
number of most recent weekly fulls, plus a settable number of older
fulls that are 2, 4, 8, or 16 weeks apart).
Incremental Backup
An incremental backup is a backup of files that have changed since
the last successful full or incremental backup. Starting in
BackupPC 3.0 multi-level incrementals are supported. A full backup
has level 0. A new incremental of level N will backup all files
that have changed since the most recent backup of a lower level.
$Conf{IncrLevels} is used to specify the level of each successive
incremental. The default value is all level 1, which makes the
behavior the same as earlier versions of BackupPC: each incremental
will back up all the files that changed since the last full (level
0).
For SMB and tar, BackupPC uses the modification time (mtime) to
determine which files have changed since the last lower-level
backup. That means SMB and tar incrementals are not able to detect
deleted files, renamed files or new files whose modification time
is prior to the last lower-level backup.
Rsync is more clever: any files whose attributes have changed (ie:
uid, gid, mtime, modes, size) since the last full are backed up.
Deleted, new files and renamed files are detected by Rsync
incrementals.
BackupPC can also be configured to keep a certain number of
incremental backups, and to keep a smaller number of very old
incremental backups. If multi-level incrementals are specified
then it is likely that more incrementals will need to be kept since
lower-level incrementals (and the full backup) are needed to
reconstruct a higher-level incremental.
BackupPC "fills-in" incremental backups when browsing or restoring,
based on the levels of each backup, giving every backup a "full"
appearance. This makes browsing and restoring backups much easier:
you can restore from any one backup independent of whether it was
an incremental or full.
Partial Backup
When a full backup fails or is canceled, and some files have
already been backed up, BackupPC keeps a partial backup containing
just the files that were backed up successfully. The partial
backup is removed when the next successful backup completes, or if
another full backup fails resulting in a newer partial backup. A
failed full backup that has not backed up any files, or any failed
incremental backup, is removed; no partial backup is saved in these
cases.
The partial backup may be browsed or used to restore files just
like a successful full or incremental backup.
With the rsync transfer method the partial backup is used to resume
the next full backup, avoiding the need to retransfer the file data
already in the partial backup.
Identical Files
BackupPC pools identical files using hardlinks. By "identical
files" we mean files with identical contents, not necessary the
same permissions, ownership or modification time. Two files might
have different permissions, ownership, or modification time but
will still be pooled whenever the contents are identical. This is
possible since BackupPC stores the file meta-data (permissions,
ownership, and modification time) separately from the file
contents.
Backup Policy
Based on your site's requirements you need to decide what your
backup policy is. BackupPC is not designed to provide exact re-
imaging of failed disks. See Limitations for more information.
However, the addition of tar transport for linux/unix clients, plus
full support for special file types and unix attributes in v1.4.0
likely means an exact image of a linux/unix file system can be
made.
BackupPC saves backups onto disk. Because of pooling you can
relatively economically keep several weeks of old backups.
At some sites the disk-based backup will be adequate, without a
secondary tape backup. This system is robust to any single failure:
if a client disk fails or loses files, the BackupPC server can be
used to restore files. If the server disk fails, BackupPC can be
restarted on a fresh file system, and create new backups from the
clients. The chance of the server disk failing can be made very
small by spending more money on increasingly better RAID systems.
However, there is still the risk of catastrophic events like fires
or earthquakes that can destroy both the BackupPC server and the
clients it is backing up if they are physically nearby.
Some sites might choose to do periodic backups to tape or cd/dvd.
This backup can be done perhaps weekly using the archive function
of BackupPC.
Other users have reported success with removable disks to rotate
the BackupPC data drives, or using rsync to mirror the BackupPC
data pool offsite.
Resources
BackupPC home page
The BackupPC Open Source project is hosted on SourceForge. The
home page can be found at:
http://backuppc.sourceforge.net
This page has links to the current documentation, the SourceForge
project page and general information.
SourceForge project
The SourceForge project page is at:
http://sourceforge.net/projects/backuppc
This page has links to the current releases of BackupPC.
BackupPC Wiki
BackupPC has a Wiki at <http://backuppc.wiki.sourceforge.net>.
Everyone is encouraged to contribute to the Wiki. Anyone with a
SourceForge account can edit the Wiki.
The old FAQ is at <http://backuppc.sourceforge.net/faq>, but is
deprecated in favor of the Wiki.
Mailing lists
Three BackupPC mailing lists exist for announcements (backuppc-
announce), developers (backuppc-devel), and a general user list for
support, asking questions or any other topic relevant to BackupPC
(backuppc-users).
The lists are archived on SourceForge and Gmane. The SourceForge
lists are not always up to date and the searching is limited, so
Gmane is a good alternative. See:
http://news.gmane.org/index.php?prefix=gmane.comp.sysutils.backup.backuppc
http://sourceforge.net/mailarchive/forum.php?forum=backuppc-users
You can subscribe to these lists by visiting:
http://lists.sourceforge.net/lists/listinfo/backuppc-announce
http://lists.sourceforge.net/lists/listinfo/backuppc-users
http://lists.sourceforge.net/lists/listinfo/backuppc-devel
The backuppc-announce list is moderated and is used only for
important announcements (eg: new versions). It is low traffic.
You only need to subscribe to one of backuppc-announce and
backuppc-users: backuppc-users also receives any messages on
backuppc-announce.
The backuppc-devel list is only for developers who are working on
BackupPC. Do not post questions or support requests there. But
detailed technical discussions should happen on this list.
To post a message to the backuppc-users list, send an email to
backuppc-users@lists.sourceforge.net
Do not send subscription requests to this address!
Other Programs of Interest
If you want to mirror linux or unix files or directories to a
remote server you should use rsync, <http://rsync.samba.org>.
BackupPC uses rsync as a transport mechanism; if you are already an
rsync user you can think of BackupPC as adding efficient storage
(compression and pooling) and a convenient user interface to rsync.
Two popular open source packages that do tape backup are Amanda
(<http://www.amanda.org>) and Bacula (<http://www.bacula.org>).
Amanda can also backup WinXX machines to tape using samba. These
packages can be used as back ends to BackupPC to backup the
BackupPC server data to tape.
Various programs and scripts use rsync to provide hardlinked
backups. See, for example, Mike Rubel's site
(<http://www.mikerubel.org/computers/rsync_snapshots>), JW
Schultz's dirvish (<http://www.dirvish.org/>), Ben Escoto's rdiff-
backup (<http://www.nongnu.org/rdiff-backup>), and John Bowman's
rlbackup (<http://www.math.ualberta.ca/imaging/rlbackup>).
Unison is a utility that can do two-way, interactive,
synchronization. See <http://freshmeat.net/projects/unison>. An
external wrapper around rsync that maintains transfer data to
enable two-way synchronization is drsync; see
<http://freshmeat.net/projects/drsync>.
BackupPC provides many additional features, such as compressed
storage, hardlinking any matching files (rather than just files
with the same name), and storing special files without root
privileges. But these other programs provide simple, effective and
fast solutions and are definitely worthy of consideration.
Road map
The new features planned for future releases of BackupPC are at
<http://backuppc.sourceforge.net/faq/roadMap.html>.
Comments and suggestions are welcome.
You can help
BackupPC is free. I work on BackupPC because I enjoy doing it and I
like to contribute to the open source community.
BackupPC already has more than enough features for my own needs. The
main compensation for continuing to work on BackupPC is knowing that
more and more people find it useful. So feedback is certainly
appreciated, both positive and negative.
Beyond being a satisfied user and telling other people about it,
everyone is encouraged to add links to
<http://backuppc.sourceforge.net> (I'll see them via Google) or
otherwise publicize BackupPC. Unlike the commercial products in this
space, I have a zero budget (in both time and money) for marketing, PR
and advertising, so it's up to all of you! Feel free to vote for
BackupPC at <http://freshmeat.net/projects/backuppc>.
Also, everyone is encouraged to contribute patches, bug reports,
feature and design suggestions, new code, Wiki additions (you can do
those directly) and documentation corrections or improvements.
Answering questions on the mailing list is a big help too.
Installing BackupPC
Requirements
BackupPC requires:
o A linux, solaris, or unix based server with a substantial amount of
free disk space (see the next section for what that means). The CPU
and disk performance on this server will determine how many
simultaneous backups you can run. You should be able to run 4-8
simultaneous backups on a moderately configured server.
Several users have reported significantly better performance using
reiserfs compared to ext3 for the BackupPC data file system. It is
also recommended you consider either an LVM or RAID setup (either
in HW or SW; eg: 3Ware RAID5) so that you can expand the file
system as necessary.
When BackupPC starts with an empty pool, all the backup data will
be written to the pool on disk. After more backups are done, a
higher percentage of incoming files will already be in the pool.
BackupPC is able to avoid writing to disk new files that are
already in the pool. So over time disk writes will reduce
significantly (by perhaps a factor of 20 or more), since eventually
95% or more of incoming backup files are typically in the pool.
Disk reads from the pool are still needed to do file compares to
verify files are an exact match. So, with a mature pool, if a
relatively fast client generates data at say 1MB/sec, and you run 4
simultaneous backups, there will be an average server disk load of
about 4MB/sec reads and 0.2MB/sec writes (assuming 95% of the
incoming files are in the pool). These rates will be perhaps 40%
lower if compression is on.
o Perl version 5.8.0 or later. If you don't have perl, please see
<http://www.cpan.org>.
o Perl modules Compress::Zlib, Archive::Zip and File::RsyncP. Try
"perldoc Compress::Zlib" and "perldoc Archive::Zip" to see if you
have these modules. If not, fetch them from <http://www.cpan.org>
and see the instructions below for how to build and install them.
The File::RsyncP module is available from
<http://perlrsync.sourceforge.net> or CPAN. You'll need to install
the File::RsyncP module if you want to use Rsync as a transport
method.
o If you are using smb to backup WinXX machines you need smbclient
and nmblookup from the samba package. You will also need nmblookup
if you are backing up linux/unix DHCP machines. See
<http://www.samba.org>. Samba versions 3.x are stable and now
recommended instead of 2.x.
See <http://www.samba.org> for source and binaries. It's pretty
easy to fetch and compile samba, and just grab smbclient and
nmblookup, without doing the installation. Alternatively,
<http://www.samba.org> has binary distributions for most platforms.
o If you are using tar to backup linux/unix machines you should have
version 1.13.7 at a minimum, with version 1.13.20 or higher
recommended. Use "tar --version" to check your version. Various
GNU mirrors have the newest versions of tar, see for example
<http://www.funet.fi/pub/gnu/alpha/gnu/tar>. As of July 2006 the
latest version is 1.15.1.
o If you are using rsync to backup linux/unix machines you should
have version 2.6.3 or higher on each client machine. See
<http://rsync.samba.org>. Use "rsync --version" to check your
version.
For BackupPC to use Rsync you will also need to install the perl
File::RsyncP module, which is available from
<http://perlrsync.sourceforge.net>. Version 0.68 or later is
required.
o The Apache web server, see <http://www.apache.org>, preferably
built with mod_perl support.
What type of storage space do I need?
BackupPC uses hardlinks to pool files common to different backups.
Therefore BackupPC's data store (__TOPDIR__) must point to a single
file system that supports hardlinks. You cannot split this file system
with multiple mount points or using symbolic links to point a sub-
directory to a different file system (it is ok to use a single symbolic
link at the top-level directory (__TOPDIR__) to point the entire data
store somewhere else). You can of course use any kind of RAID system
or logical volume manager that combines the capacity of multiple disks
into a single, larger, file system. Such approaches have the advantage
that the file system can be expanded without having to copy it.
Any standard linux or unix file system supports hardlinks. NFS mounted
file systems work too (provided the underlying file system supports
hardlinks). But windows based FAT and NTFS file systems will not work.
Starting with BackupPC 3.1.0, run-time checks are done at startup and
at the start of each backup to ensure that the file system can support
hardlinks, since this is a common area of configuration problems.
How much disk space do I need?
Here's one real example for an environment that is backing up 65
laptops with compression off. Each full backup averages 3.2GB. Each
incremental backup averages about 0.2GB. Storing one full backup and
two incremental backups per laptop is around 240GB of raw data. But
because of the pooling of identical files, only 87GB is used. This is
without compression.
Another example, with compression on: backing up 95 laptops, where each
backup averages 3.6GB and each incremental averages about 0.3GB.
Keeping three weekly full backups, and six incrementals is around
1200GB of raw data. Because of pooling and compression, only 150GB is
needed.
Here's a rule of thumb. Add up the disk usage of all the machines you
want to backup (210GB in the first example above). This is a rough
minimum space estimate that should allow a couple of full backups and
at least half a dozen incremental backups per machine. If compression
is on you can reduce the storage requirements by maybe 30-40%. Add
some margin in case you add more machines or decide to keep more old
backups.
Your actual mileage will depend upon the types of clients, operating
systems and applications you have. The more uniform the clients and
applications the bigger the benefit from pooling common files.
For example, the Eudora email tool stores each mail folder in a
separate file, and attachments are extracted as separate files. So in
the sadly common case of a large attachment emailed to many recipients,
Eudora will extract the attachment into a new file. When these machines
are backed up, only one copy of the file will be stored on the server,
even though the file appears in many different full or incremental
backups. In this sense Eudora is a "friendly" application from the
point of view of backup storage requirements.
An example at the other end of the spectrum is Outlook. Everything
(email bodies, attachments, calendar, contact lists) is stored in a
single file, which often becomes huge. Any change to this file requires
a separate copy of the file to be saved during backup. Outlook is even
more troublesome, since it keeps this file locked all the time, so it
cannot be read by smbclient whenever Outlook is running. See the
Limitations section for more discussion of this problem.
In addition to total disk space, you should make sure you have plenty
of inodes on your BackupPC data partition. Some users have reported
running out of inodes on their BackupPC data partition. So even if you
have plenty of disk space, BackupPC will report failures when the
inodes are exhausted. This is a particular problem with ext2/ext3 file
systems that have a fixed number of inodes when the file system is
built. Use "df -i" to see your inode usage.
Step 1: Getting BackupPC
Some linux distributions now include BackupPC. The Debian
distribution, supported by Ludovic Drolez, can be found at
<http://packages.debian.org/backuppc> and is included in the current
stable Debian release. On Debian, BackupPC can be installed with the
command:
apt-get install backuppc
In the future there might be packages for Gentoo and other linux
flavors. If the packaged version is older than the released version
then you may want to install the latest version as described below.
Otherwise, manually fetching and installing BackupPC is easy. Start by
downloading the latest version from <http://backuppc.sourceforge.net>.
Hit the "Code" button, then select the "backuppc" or "backuppc-beta"
package and download the latest version.
Step 2: Installing the distribution
Note: most information in this step is only relevant if you build and
install BackupPC yourself. If you use a package provided by a
distribution, the package management system should take of installing
any needed dependencies.
First off, there are three perl modules you should install. These are
all optional, but highly recommended:
Compress::Zlib
To enable compression, you will need to install Compress::Zlib from
<http://www.cpan.org>. You can run "perldoc Compress::Zlib" to see
if this module is installed.
Archive::Zip
To support restore via Zip archives you will need to install
Archive::Zip, also from <http://www.cpan.org>. You can run
"perldoc Archive::Zip" to see if this module is installed.
XML::RSS
To support the RSS feature you will need to install XML::RSS, also
from <http://www.cpan.org>. There is not need to install this
module if you don't plan on using RSS. You can run "perldoc
XML::RSS" to see if this module is installed.
File::RsyncP
To use rsync and rsyncd with BackupPC you will need to install
File::RsyncP. You can run "perldoc File::RsyncP" to see if this
module is installed. File::RsyncP is available from
<http://perlrsync.sourceforge.net>. Version 0.52 or later is
required.
To build and install these packages, fetch the tar.gz file and then run
these commands:
tar zxvf Archive-Zip-1.16.tar.gz
cd Archive-Zip-1.16
perl Makefile.PL
make
make test
make install
The same sequence of commands can be used for each module.
Now let's move onto BackupPC itself. After fetching
BackupPC-3.1.0.tar.gz, run these commands as root:
tar zxf BackupPC-3.1.0.tar.gz
cd BackupPC-3.1.0
perl configure.pl
In the future this release might also have patches available on the
SourceForge site. These patch files are text files, with a name of the
form
BackupPC-3.1.0plN.diff
where N is the patch level, eg: pl2 is patch-level 2. These patch
files are cumulative: you only need apply the last patch file, not all
the earlier patch files. If a patch file is available, eg:
BackupPC-3.1.0pl2.diff, you should apply the patch after extracting the
tar file:
# fetch BackupPC-3.1.0.tar.gz
# fetch BackupPC-3.1.0pl2.diff
tar zxf BackupPC-3.1.0.tar.gz
cd BackupPC-3.1.0
patch -p0 < ../BackupPC-3.1.0pl2.diff
perl configure.pl
A patch file includes comments that describe that bug fixes and
changes. Feel free to review it before you apply the patch.
The configure.pl script also accepts command-line options if you wish
to run it in a non-interactive manner. It has self-contained
documentation for all the command-line options, which you can read with
perldoc:
perldoc configure.pl
Starting with BackupPC 3.0.0, the configure.pl script by default
complies with the file system hierarchy (FHS) conventions. The major
difference compared to earlier versions is that by default
configuration files will be stored in /etc/BackupPC rather than below
the data directory, __TOPDIR__/conf, and the log files will be stored
in /var/log/BackupPC rather than below the data directory,
__TOPDIR__/log.
Note that distributions may choose to use different locations for
BackupPC files than these defaults.
If you are upgrading from an earlier version the configure.pl script
will keep the configuration files and log files in their original
location.
When you run configure.pl you will be prompted for the full paths of
various executables, and you will be prompted for the following
information.
BackupPC User
It is best if BackupPC runs as a special user, eg backuppc, that
has limited privileges. It is preferred that backuppc belongs to a
system administrator group so that sys admin members can browse
BackupPC files, edit the configuration files and so on. Although
configurable, the default settings leave group read permission on
pool files, so make sure the BackupPC user's group is chosen
restrictively.
On this installation, this is __BACKUPPCUSER__.
For security purposes you might choose to configure the BackupPC
user with the shell set to /bin/false. Since you might need to run
some BackupPC programs as the BackupPC user for testing purposes,
you can use the -s option to su to explicitly run a shell, eg:
su -s /bin/bash __BACKUPPCUSER__
Depending upon your configuration you might also need the -l
option.
Data Directory
You need to decide where to put the data directory, below which all
the BackupPC data is stored. This needs to be a big file system.
On this installation, this is __TOPDIR__.
Install Directory
You should decide where the BackupPC scripts, libraries and
documentation should be installed, eg: /usr/local/BackupPC.
On this installation, this is __INSTALLDIR__.
CGI bin Directory
You should decide where the BackupPC CGI script resides. This will
usually be below Apache's cgi-bin directory.
It is also possible to use a different directory and use Apache's
``<Directory>'' directive to specifiy that location. See the
Apache HTTP Server documentation for additional information.
On this installation, this is __CGIDIR__.
Apache image Directory
A directory where BackupPC's images are stored so that Apache can
serve them. You should ensure this directory is readable by Apache
and create a symlink to this directory from the BackupPC CGI bin
Directory.
Config and Log Directories
In this installation the configuration and log directories are
located in the following locations:
__CONFDIR__/config.pl main config file
__CONFDIR__/hosts hosts file
__CONFDIR__/pc/HOST.pl per-pc config file
__LOGDIR__/BackupPC log files, pid, status
The configure.pl script doesn't prompt for these locations but they
can be set for new installations using command-line options.
Step 3: Setting up config.pl
After running configure.pl, browse through the config file,
__CONFDIR__/config.pl, and make sure all the default settings are
correct. In particular, you will need to decide whether to use smb, tar
or rsync transport (or whether to set it on a per-PC basis) and set the
relevant parameters for that transport method. See the section Client
Setup for more details.
Step 4: Setting up the hosts file
The file __CONFDIR__/hosts contains the list of clients to backup.
BackupPC reads this file in three cases:
o Upon startup.
o When BackupPC is sent a HUP (-1) signal. Assuming you installed
the init.d script, you can also do this with "/etc/init.d/backuppc
reload".
o When the modification time of the hosts file changes. BackupPC
checks the modification time once during each regular wakeup.
Whenever you change the hosts file (to add or remove a host) you can
either do a kill -HUP BackupPC_pid or simply wait until the next
regular wakeup period.
Each line in the hosts file contains three fields, separated by white
space:
Host name
This is typically the host name or NetBios name of the client
machine and should be in lower case. The host name can contain
spaces (escape with a backslash), but it is not recommended.
Please read the section How BackupPC Finds Hosts.
In certain cases you might want several distinct clients to refer
to the same physical machine. For example, you might have a
database you want to backup, and you want to bracket the backup of
the database with shutdown/restart using $Conf{DumpPreUserCmd} and
$Conf{DumpPostUserCmd}. But you also want to backup the rest of
the machine while the database is still running. In the case you
can specify two different clients in the host file, using any
mnemonic name (eg: myhost_mysql and myhost), and use
$Conf{ClientNameAlias} in myhost_mysql's config.pl to specify the
real host name of the machine.
DHCP flag
Starting with v2.0.0 the way hosts are discovered has changed and
now in most cases you should specify 0 for the DHCP flag, even if
the host has a dynamically assigned IP address. Please read the
section How BackupPC Finds Hosts to understand whether you need to
set the DHCP flag.
You only need to set DHCP to 1 if your client machine doesn't
respond to the NetBios multicast request:
nmblookup myHost
but does respond to a request directed to its IP address:
nmblookup -A W.X.Y.Z
If you do set DHCP to 1 on any client you will need to specify the
range of DHCP addresses to search is specified in
$Conf{DHCPAddressRanges}.
Note also that the $Conf{ClientNameAlias} feature does not work for
clients with DHCP set to 1.
User name
This should be the unix login/email name of the user who "owns" or
uses this machine. This is the user who will be sent email about
this machine, and this user will have permission to
stop/start/browse/restore backups for this host. Leave this blank
if no specific person should receive email or be allowed to
stop/start/browse/restore backups for this host. Administrators
will still have full permissions.
More users
Additional user names, separate by commas and with no white space,
can be specified. These users will also have full permission in
the CGI interface to stop/start/browse/restore backups for this
host. These users will not be sent email about this host.
The first non-comment line of the hosts file is special: it contains
the names of the columns and should not be edited.
Here's a simple example of a hosts file:
host dhcp user moreUsers
farside 0 craig jim,dave
larson 1 gary andy
Step 5: Client Setup
Three methods for getting backup data from a client are supported: smb,
tar and rsync. Smb or rsync are the preferred methods for WinXX
clients and rsync or tar are the preferred methods for
linux/unix/MacOSX clients.
The transfer method is set using the $Conf{XferMethod} configuration
setting. If you have a mixed environment (ie: you will use smb for some
clients and tar for others), you will need to pick the most common
choice for $Conf{XferMethod} for the main config.pl file, and then
override it in the per-PC config file for those hosts that will use the
other method. (Or you could run two completely separate instances of
BackupPC, with different data directories, one for WinXX and the other
for linux/unix, but then common files between the different machine
types will duplicated.)
Here are some brief client setup notes:
WinXX
One setup for WinXX clients is to set $Conf{XferMethod} to "smb".
Actually, rsyncd is the better method for WinXX if you are prepared
to run rsync/cygwin on your WinXX client.
If you want to use rsyncd for WinXX clients you can find a pre-
packaged zip file on <http://backuppc.sourceforge.net>. The package
is called cygwin-rsync. It contains rsync.exe, template setup files
and the minimal set of cygwin libraries for everything to run. The
README file contains instructions for running rsync as a service,
so it starts automatically everytime you boot your machine. If you
use rsync to backup WinXX machines, be sure to set
$Conf{ClientCharset} correctly (eg: 'cp1252') so that the WinXX
file name encoding is correctly converted to utf8.
Otherwise, to use SMB, you can either create shares for the data
you want to backup or your can use the existing C$ share. To
create a new share, open "My Computer", right click on the drive
(eg: C), and select "Sharing..." (or select "Properties" and select
the "Sharing" tab). In this dialog box you can enable sharing,
select the share name and permissions.
All Windows NT based OS (NT, 2000, XP Pro), are configured by
default to share the entire C drive as C$. This is a special share
used for various administration functions, one of which is to grant
access to backup operators. All you need to do is create a new
domain user, specifically for backup. Then add the new backup user
to the built in "Backup Operators" group. You now have backup
capability for any directory on any computer in the domain in one
easy step. This avoids using administrator accounts and only grants
permission to do exactly what you want for the given user, i.e.:
backup. Also, for additional security, you may wish to deny the
ability for this user to logon to computers in the default domain
policy.
If this machine uses DHCP you will also need to make sure the
NetBios name is set. Go to Control Panel|System|Network
Identification (on Win2K) or Control Panel|System|Computer Name (on
WinXP). Also, you should go to Control Panel|Network
Connections|Local Area Connection|Properties|Internet Protocol
(TCP/IP)|Properties|Advanced|WINS and verify that NetBios is not
disabled.
The relevant configuration settings are $Conf{SmbShareName},
$Conf{SmbShareUserName}, $Conf{SmbSharePasswd},
$Conf{SmbClientPath}, $Conf{SmbClientFullCmd},
$Conf{SmbClientIncrCmd} and $Conf{SmbClientRestoreCmd}.
BackupPC needs to know the smb share user name and password for a
client machine that uses smb. The user name is specified in
$Conf{SmbShareUserName}. There are four ways to tell BackupPC the
smb share password:
o As an environment variable BPC_SMB_PASSWD set before BackupPC
starts. If you start BackupPC manually the BPC_SMB_PASSWD
variable must be set manually first. For backward
compatibility for v1.5.0 and prior, the environment variable
PASSWD can be used if BPC_SMB_PASSWD is not set. Warning: on
some systems it is possible to see environment variables of
running processes.
o Alternatively the BPC_SMB_PASSWD setting can be included in
/etc/init.d/backuppc, in which case you must make sure this
file is not world (other) readable.
o As a configuration variable $Conf{SmbSharePasswd} in
__CONFDIR__/config.pl. If you put the password here you must
make sure this file is not world (other) readable.
o As a configuration variable $Conf{SmbSharePasswd} in the per-PC
configuration file (__CONFDIR__/pc/$host.pl or
__TOPDIR__/pc/$host/config.pl in non-FHS versions of BackupPC).
You will have to use this option if the smb share password is
different for each host. If you put the password here you must
make sure this file is not world (other) readable.
Placement and protection of the smb share password is a possible
security risk, so please double-check the file and directory
permissions. In a future version there might be support for
encryption of this password, but a private key will still have to
be stored in a protected place. Suggestions are welcome.
As an alternative to setting $Conf{XferMethod} to "smb" (using
smbclient) for WinXX clients, you can use an smb network filesystem
(eg: ksmbfs or similar) on your linux/unix server to mount the
share, and then set $Conf{XferMethod} to "tar" (use tar on the
network mounted file system).
Also, to make sure that file names with special characters are
correctly transferred by smbclient you should make sure that the
smb.conf file has (for samba 3.x):
[global]
unix charset = UTF8
UTF8 is the default setting, so if the parameter is missing then it
is ok. With this setting $Conf{ClientCharset} should be emtpy,
since smbclient has already converted the file names to utf8.
Linux/Unix
The preferred setup for linux/unix clients is to set
$Conf{XferMethod} to "rsync", "rsyncd" or "tar".
You can use either rsync, smb, or tar for linux/unix machines. Smb
requires that the Samba server (smbd) be run to provide the shares.
Since the smb protocol can't represent special files like symbolic
links and fifos, tar and rsync are the better transport methods for
linux/unix machines. (In fact, by default samba makes symbolic
links look like the file or directory that they point to, so you
could get an infinite loop if a symbolic link points to the current
or parent directory. If you really need to use Samba shares for
linux/unix backups you should turn off the "follow symlinks" samba
config setting. See the smb.conf manual page.)
The requirements for each Xfer Method are:
tar You must have GNU tar on the client machine. Use "tar
--version" or "gtar --version" to verify. The version should
be at least 1.13.7, and 1.13.20 or greater is recommended. Tar
is run on the client machine via rsh or ssh.
The relevant configuration settings are $Conf{TarClientPath},
$Conf{TarShareName}, $Conf{TarClientCmd}, $Conf{TarFullArgs},
$Conf{TarIncrArgs}, and $Conf{TarClientRestoreCmd}.
rsync
You should have at least rsync 2.6.3, and the latest version is
recommended. Rsync is run on the remote client via rsh or ssh.
The relevant configuration settings are $Conf{RsyncClientPath},
$Conf{RsyncClientCmd}, $Conf{RsyncClientRestoreCmd},
$Conf{RsyncShareName}, $Conf{RsyncArgs}, and
$Conf{RsyncRestoreArgs}.
rsyncd
You should have at least rsync 2.6.3, and the latest version is
recommended. In this case the rsync daemon should be running
on the client machine and BackupPC connects directly to it.
The relevant configuration settings are
$Conf{RsyncdClientPort}, $Conf{RsyncdUserName},
$Conf{RsyncdPasswd}, $Conf{RsyncdAuthRequired},
$Conf{RsyncShareName}, $Conf{RsyncArgs}, and
$Conf{RsyncRestoreArgs}. $Conf{RsyncShareName} is the name of
an rsync module (ie: the thing in square brackets in rsyncd's
conf file -- see rsyncd.conf), not a file system path.
Be aware that rsyncd will remove the leading '/' from path
names in symbolic links if you specify "use chroot = no" in the
rsynd.conf file. See the rsyncd.conf manual page for more
information.
You need to set $Conf{ClientCharset} to the client's charset so
that file names are correctly converted to utf8. Use "locale
charmap" on the client to see its charset.
For linux/unix machines you should not backup "/proc". This
directory contains a variety of files that look like regular files
but they are special files that don't need to be backed up (eg:
/proc/kcore is a regular file that contains physical memory). See
$Conf{BackupFilesExclude}. It is safe to back up /dev since it
contains mostly character-special and block-special files, which
are correctly handed by BackupPC (eg: backing up /dev/hda5 just
saves the block-special file information, not the contents of the
disk).
Alternatively, rather than backup all the file systems as a single
share ("/"), it is easier to restore a single file system if you
backup each file system separately. To do this you should list
each file system mount point in $Conf{TarShareName} or
$Conf{RsyncShareName}, and add the --one-file-system option to
$Conf{TarClientCmd} or $Conf{RsyncArgs}. In this case there is no
need to exclude /proc explicitly since it looks like a different
file system.
Next you should decide whether to run tar over ssh, rsh or nfs. Ssh
is the preferred method. Rsh is not secure and therefore not
recommended. Nfs will work, but you need to make sure that the
BackupPC user (running on the server) has sufficient permissions to
read all the files below the nfs mount.
Ssh allows BackupPC to run as a privileged user on the client (eg:
root), since it needs sufficient permissions to read all the backup
files. Ssh is setup so that BackupPC on the server (an otherwise
low privileged user) can ssh as root on the client, without being
prompted for a password. There are two common versions of ssh: v1
and v2. Here are some instructions for one way to setup ssh.
(Check which version of SSH you have by typing "ssh" or "man ssh".)
MacOSX
In general this should be similar to Linux/Unix machines. In
versions 10.4 and later, the native MacOSX tar works, and also
supports resource forks. xtar is another option, and rsync works
too (although the MacOSX-supplied rsync has an extension for
extended attributes that is not compatible with standard rsync).
SSH Setup
SSH is a secure way to run tar or rsync on a backup client to
extract the data. SSH provides strong authentication and
encryption of the network data.
Note that if you run rsyncd (rsync daemon), ssh is not used. In
this case, rsyncd provides its own authentication, but there is no
encryption of network data. If you want encryption of network data
you can use ssh to create a tunnel, or use a program like stunnel.
Setup instructions for ssh can be found at
<http://backuppc.sourceforge.net/faq/ssh.html>.
Clients that use DHCP
If a client machine uses DHCP BackupPC needs some way to find the
IP address given the host name. One alternative is to set dhcp to
1 in the hosts file, and BackupPC will search a pool of IP
addresses looking for hosts. More efficiently, it is better to set
dhcp = 0 and provide a mechanism for BackupPC to find the IP
address given the host name.
For WinXX machines BackupPC uses the NetBios name server to
determine the IP address given the host name. For unix machines
you can run nmbd (the NetBios name server) from the Samba
distribution so that the machine responds to a NetBios name
request. See the manual page and Samba documentation for more
information.
Alternatively, you can set $Conf{NmbLookupFindHostCmd} to any
command that returns the IP address given the host name.
Please read the section How BackupPC Finds Hosts for more details.
Step 6: Running BackupPC
The installation contains an init.d backuppc script that can be copied
to /etc/init.d so that BackupPC can auto-start on boot. See
init.d/README for further instructions.
BackupPC should be ready to start. If you installed the init.d script,
then you should be able to run BackupPC with:
/etc/init.d/backuppc start
(This script can also be invoked with "stop" to stop BackupPC and
"reload" to tell BackupPC to reload config.pl and the hosts file.)
Otherwise, just run
__INSTALLDIR__/bin/BackupPC -d
as user __BACKUPPCUSER__. The -d option tells BackupPC to run as a
daemon (ie: it does an additional fork).
Any immediate errors will be printed to stderr and BackupPC will quit.
Otherwise, look in __LOGDIR__/LOG and verify that BackupPC reports it
has started and all is ok.
Step 7: Talking to BackupPC
You should verify that BackupPC is running by using
BackupPC_serverMesg. This sends a message to BackupPC via the unix (or
TCP) socket and prints the response. Like all BackupPC programs,
BackupPC_serverMesg should be run as the BackupPC user
(__BACKUPPCUSER__), so you should
su __BACKUPPCUSER__
before running BackupPC_serverMesg. If the BackupPC user is configured
with /bin/false as the shell, you can use the -s option to su to
explicitly run a shell, eg:
su -s /bin/bash __BACKUPPCUSER__
Depending upon your configuration you might also need the -l option.
You can request status information and start and stop backups using
this interface. This socket interface is mainly provided for the CGI
interface (and some of the BackupPC sub-programs use it too). But
right now we just want to make sure BackupPC is happy. Each of these
commands should produce some status output:
__INSTALLDIR__/bin/BackupPC_serverMesg status info
__INSTALLDIR__/bin/BackupPC_serverMesg status jobs
__INSTALLDIR__/bin/BackupPC_serverMesg status hosts
The output should be some hashes printed with Data::Dumper. If it
looks cryptic and confusing, and doesn't look like an error message,
then all is ok.
The jobs status should initially show just BackupPC_trashClean. The
hosts status should produce a list of every host you have listed in
__CONFDIR__/hosts as part of a big cryptic output line.
You can also request that all hosts be queued:
__INSTALLDIR__/bin/BackupPC_serverMesg backup all
At this point you should make sure the CGI interface works since it
will be much easier to see what is going on. That's our next subject.
Step 8: Checking email delivery
The script BackupPC_sendEmail sends status and error emails to the
administrator and users. It is usually run each night by
BackupPC_nightly.
To verify that it can run sendmail and deliver email correctly you
should ask it to send a test email to you:
su __BACKUPPCUSER__
__INSTALLDIR__/bin/BackupPC_sendEmail -u MYNAME@MYDOMAIN.COM
BackupPC_sendEmail also takes a -c option that checks if BackupPC is
running, and it sends an email to $Conf{EMailAdminUserName} if it is
not. That can be used as a keep-alive check by adding
__INSTALLDIR__/bin/BackupPC_sendEmail -c
to __BACKUPPCUSER__'s cron.
The -t option to BackupPC_sendEmail causes it to print the email
message instead of invoking sendmail to deliver the message.
Step 9: CGI interface
The CGI interface script, BackupPC_Admin, is a powerful and flexible
way to see and control what BackupPC is doing. It is written for an
Apache server. If you don't have Apache, see <http://www.apache.org>.
There are two options for setting up the CGI interface: standard mode
and using mod_perl. Mod_perl provides much higher performance (around
15x) and is the best choice if your Apache was built with mod_perl
support. To see if your apache was built with mod_perl run this
command:
httpd -l | egrep mod_perl
If this prints mod_perl.c then your Apache supports mod_perl.
Note: on some distributions (like Debian) the command is not ``httpd'',
but ``apache'' or ``apache2''. Those distributions will generally also
use ``apache'' for the Apache user account and configuration files.
Using mod_perl with BackupPC_Admin requires a dedicated Apache to be
run as the BackupPC user (__BACKUPPCUSER__). This is because
BackupPC_Admin needs permission to access various files in BackupPC's
data directories. In contrast, the standard installation (without
mod_perl) solves this problem by having BackupPC_Admin installed as
setuid to the BackupPC user, so that BackupPC_Admin runs as the
BackupPC user.
Here are some specifics for each setup:
Standard Setup
The CGI interface should have been installed by the configure.pl
script in __CGIDIR__/BackupPC_Admin. BackupPC_Admin should have
been installed as setuid to the BackupPC user (__BACKUPPCUSER__),
in addition to user and group execute permission.
You should be very careful about permissions on BackupPC_Admin and
the directory __CGIDIR__: it is important that normal users cannot
directly execute or change BackupPC_Admin, otherwise they can
access backup files for any PC. You might need to change the group
ownership of BackupPC_Admin to a group that Apache belongs to so
that Apache can execute it (don't add "other" execute permission!).
The permissions should look like this:
ls -l __CGIDIR__/BackupPC_Admin
-swxr-x--- 1 __BACKUPPCUSER__ web 82406 Jun 17 22:58 __CGIDIR__/BackupPC_Admin
The setuid script won't work unless perl on your machine was
installed with setuid emulation. This is likely the problem if you
get an error saying such as "Wrong user: my userid is 25, instead
of 150", meaning the script is running as the httpd user, not the
BackupPC user. This is because setuid scripts are disabled by the
kernel in most flavors of unix and linux.
To see if your perl has setuid emulation, see if there is a program
called sperl5.8.0 (or sperl5.8.2 etc, based on your perl version)
in the place where perl is installed. If you can't find this
program, then you have two options: rebuild and reinstall perl with
the setuid emulation turned on (answer "y" to the question "Do you
want to do setuid/setgid emulation?" when you run perl's configure
script), or switch to the mod_perl alternative for the CGI script
(which doesn't need setuid to work).
Mod_perl Setup
The advantage of the mod_perl setup is that no setuid script is
needed, and there is a huge performance advantage. Not only does
all the perl code need to be parsed just once, the config.pl and
hosts files, plus the connection to the BackupPC server are cached
between requests. The typical speedup is around 15 times.
To use mod_perl you need to run Apache as user __BACKUPPCUSER__.
If you need to run multiple Apache's for different services then
you need to create multiple top-level Apache directories, each with
their own config file. You can make copies of /etc/init.d/httpd
and use the -d option to httpd to point each http to a different
top-level directory. Or you can use the -f option to explicitly
point to the config file. Multiple Apache's will run on different
Ports (eg: 80 is standard, 8080 is a typical alternative port
accessed via http://yourhost.com:8080).
Inside BackupPC's Apache http.conf file you should check the
settings for ServerRoot, DocumentRoot, User, Group, and Port. See
<http://httpd.apache.org/docs/server-wide.html> for more details.
For mod_perl, BackupPC_Admin should not have setuid permission, so
you should turn it off:
chmod u-s __CGIDIR__/BackupPC_Admin
To tell Apache to use mod_perl to execute BackupPC_Admin, add this
to Apache's 1.x httpd.conf file:
<IfModule mod_perl.c>
PerlModule Apache::Registry
PerlTaintCheck On
<Location /cgi-bin/BackupPC/BackupPC_Admin> # <--- change path as needed
SetHandler perl-script
PerlHandler Apache::Registry
Options ExecCGI
PerlSendHeader On
</Location>
</IfModule>
Apache 2.0.44 with Perl 5.8.0 on RedHat 7.1, Don Silvia reports
that this works (with tweaks from Michael Tuzi):
LoadModule perl_module modules/mod_perl.so
PerlModule Apache2
<Directory /path/to/cgi/>
SetHandler perl-script
PerlResponseHandler ModPerl::Registry
PerlOptions +ParseHeaders
Options +ExecCGI
Order deny,allow
Deny from all
Allow from 192.168.0
AuthName "Backup Admin"
AuthType Basic
AuthUserFile /path/to/user_file
Require valid-user
</Directory>
There are other optimizations and options with mod_perl. For
example, you can tell mod_perl to preload various perl modules,
which saves memory compared to loading separate copies in every
Apache process after they are forked. See Stas's definitive
mod_perl guide at <http://perl.apache.org/guide>.
BackupPC_Admin requires that users are authenticated by Apache.
Specifically, it expects that Apache sets the REMOTE_USER environment
variable when it runs. There are several ways to do this. One way is
to create a .htaccess file in the cgi-bin directory that looks like:
AuthGroupFile /etc/httpd/conf/group # <--- change path as needed
AuthUserFile /etc/http/conf/passwd # <--- change path as needed
AuthType basic
AuthName "access"
require valid-user
You will also need "AllowOverride Indexes AuthConfig" in the Apache
httpd.conf file to enable the .htaccess file. Alternatively, everything
can go in the Apache httpd.conf file inside a Location directive. The
list of users and password file above can be extracted from the NIS
passwd file.
One alternative is to use LDAP. In Apache's http.conf add these lines:
LoadModule auth_ldap_module modules/auth_ldap.so
AddModule auth_ldap.c
# cgi-bin - auth via LDAP (for BackupPC)
<Location /cgi-binBackupPC/BackupPC_Admin> # <--- change path as needed
AuthType Basic
AuthName "BackupPC login"
# replace MYDOMAIN, PORT, ORG and CO as needed
AuthLDAPURL ldap://ldap.MYDOMAIN.com:PORT/o=ORG,c=CO?uid?sub?(objectClass=*)
require valid-user
</Location>
If you want to disable the user authentication you can set
$Conf{CgiAdminUsers} to '*', which allows any user to have full access
to all hosts and backups. In this case the REMOTE_USER environment
variable does not have to be set by Apache.
Alternatively, you can force a particular user name by getting Apache
to set REMOTE_USER, eg, to hardcode the user to www you could add this
to Apache's httpd.conf:
<Location /cgi-bin/BackupPC/BackupPC_Admin> # <--- change path as needed
Setenv REMOTE_USER www
</Location>
Finally, you should also edit the config.pl file and adjust, as
necessary, the CGI-specific settings. They're near the end of the
config file. In particular, you should specify which users or groups
have administrator (privileged) access: see the config settings
$Conf{CgiAdminUserGroup} and $Conf{CgiAdminUsers}. Also, the
configure.pl script placed various images into $Conf{CgiImageDir} that
BackupPC_Admin needs to serve up. You should make sure that
$Conf{CgiImageDirURL} is the correct URL for the image directory.
See the section Fixing installation problems for suggestions on
debugging the Apache authentication setup.
How BackupPC Finds Hosts
Starting with v2.0.0 the way hosts are discovered has changed. In most
cases you should specify 0 for the DHCP flag in the conf/hosts file,
even if the host has a dynamically assigned IP address.
BackupPC (starting with v2.0.0) looks up hosts with DHCP = 0 in this
manner:
o First DNS is used to lookup the IP address given the client's name
using perl's gethostbyname() function. This should succeed for
machines that have fixed IP addresses that are known via DNS. You
can manually see whether a given host have a DNS entry according to
perl's gethostbyname function with this command:
perl -e 'print(gethostbyname("myhost") ? "ok\n" : "not found\n");'
o If gethostbyname() fails, BackupPC then attempts a NetBios
multicast to find the host. Provided your client machine is
configured properly, it should respond to this NetBios multicast
request. Specifically, BackupPC runs a command of this form:
nmblookup myhost
If this fails you will see output like:
querying myhost on 10.10.255.255
name_query failed to find name myhost
If it is successful you will see output like:
querying myhost on 10.10.255.255
10.10.1.73 myhost<00>
Depending on your netmask you might need to specify the -B option
to nmblookup. For example:
nmblookup -B 10.10.1.255 myhost
If necessary, experiment with the nmblookup command which will
return the IP address of the client given its name. Then update
$Conf{NmbLookupFindHostCmd} with any necessary options to
nmblookup.
For hosts that have the DHCP flag set to 1, these machines are
discovered as follows:
o A DHCP address pool ($Conf{DHCPAddressRanges}) needs to be
specified. BackupPC will check the NetBIOS name of each machine in
the range using a command of the form:
nmblookup -A W.X.Y.Z
where W.X.Y.Z is each candidate address from
$Conf{DHCPAddressRanges}. Any host that has a valid NetBIOS name
returned by this command (ie: matching an entry in the hosts file)
will be backed up. You can modify the specific nmblookup command
if necessary via $Conf{NmbLookupCmd}.
o You only need to use this DHCP feature if your client machine
doesn't respond to the NetBios multicast request:
nmblookup myHost
but does respond to a request directed to its IP address:
nmblookup -A W.X.Y.Z
Other installation topics
Removing a client
If there is a machine that no longer needs to be backed up (eg: a
retired machine) you have two choices. First, you can keep the
backups accessible and browsable, but disable all new backups.
Alternatively, you can completely remove the client and all its
backups.
To disable backups for a client there are two special values for
$Conf{FullPeriod} in that client's per-PC config.pl file:
-1 Don't do any regular backups on this machine. Manually
requested backups (via the CGI interface) will still occur.
-2 Don't do any backups on this machine. Manually requested
backups (via the CGI interface) will be ignored.
This will still allow the client's old backups to be browsable and
restorable.
To completely remove a client and all its backups, you should
remove its entry in the conf/hosts file, and then delete the
__TOPDIR__/pc/$host directory. Whenever you change the hosts file,
you should send BackupPC a HUP (-1) signal so that it re-reads the
hosts file. If you don't do this, BackupPC will automatically re-
read the hosts file at the next regular wakeup.
Note that when you remove a client's backups you won't initially
recover a lot of disk space. That's because the client's files are
still in the pool. Overnight, when BackupPC_nightly next runs, all
the unused pool files will be deleted and this will recover the
disk space used by the client's backups.
Copying the pool
If the pool disk requirements grow you might need to copy the
entire data directory to a new (bigger) file system. Hopefully you
are lucky enough to avoid this by having the data directory on a
RAID file system or LVM that allows the capacity to be grown in
place by adding disks.
The backup data directories contain large numbers of hardlinks. If
you try to copy the pool the target directory will occupy a lot
more space if the hardlinks aren't re-established.
The best way to copy a pool file system, if possible, is by copying
the raw device at the block level (eg: using dd). Application
level programs that understand hardlinks include the GNU cp program
with the -a option and rsync -H. However, the large number of
hardlinks in the pool will make the memory usage large and the copy
very slow. Don't forget to stop BackupPC while the copy runs.
Starting in 3.0.0 a new script bin/BackupPC_tarPCCopy can be used
to assist the copy process. Given one or more pc paths (eg:
TOPDIR/pc/HOST or TOPDIR/pc/HOST/nnn), BackupPC_tarPCCopy creates a
tar archive with all the hardlinks pointing to ../cpool/.... Any
files not hardlinked (eg: backups, LOG etc) are included verbatim.
You will need to specify the -P option to tar when you extract the
archive generated by BackupPC_tarPCCopy since the hardlink targets
are outside of the directory being extracted.
To copy a complete store (ie: __TOPDIR__) using BackupPC_tarPCCopy
you should:
o stop BackupPC so that the store is static.
o copy the cpool, conf and log directory trees using any
technique (like cp, rsync or tar) without the need to preserve
hardlinks.
o copy the pc directory using BackupPC_tarPCCopy:
su __BACKUPPCUSER__
cd NEW_TOPDIR
mkdir pc
cd pc
__INSTALLDIR__/bin/BackupPC_tarPCCopy __TOPDIR__/pc | tar xvPf -
Fixing installation problems
Please see the Wiki at <http://backuppc.wiki.sourceforge.net> for
debugging suggestions. If you find a solution to your problem that
could help other users please add it to the Wiki!
Restore functions
BackupPC supports several different methods for restoring files. The
most convenient restore options are provided via the CGI interface.
Alternatively, backup files can be restored using manual commands.
CGI restore options
By selecting a host in the CGI interface, a list of all the backups for
that machine will be displayed. By selecting the backup number you can
navigate the shares and directory tree for that backup.
BackupPC's CGI interface automatically fills incremental backups with
the corresponding full backup, which means each backup has a filled
appearance. Therefore, there is no need to do multiple restores from
the incremental and full backups: BackupPC does all the hard work for
you. You simply select the files and directories you want from the
correct backup vintage in one step.
You can download a single backup file at any time simply by selecting
it. Your browser should prompt you with the file name and ask you
whether to open the file or save it to disk.
Alternatively, you can select one or more files or directories in the
currently selected directory and select "Restore selected files". (If
you need to restore selected files and directories from several
different parent directories you will need to do that in multiple
steps.)
If you select all the files in a directory, BackupPC will replace the
list of files with the parent directory. You will be presented with a
screen that has three options:
Option 1: Direct Restore
With this option the selected files and directories are restored
directly back onto the host, by default in their original location.
Any old files with the same name will be overwritten, so use
caution. You can optionally change the target host name, target
share name, and target path prefix for the restore, allowing you to
restore the files to a different location.
Once you select "Start Restore" you will be prompted one last time
with a summary of the exact source and target files and directories
before you commit. When you give the final go ahead the restore
operation will be queued like a normal backup job, meaning that it
will be deferred if there is a backup currently running for that
host. When the restore job is run, smbclient, tar, rsync or rsyncd
is used (depending upon $Conf{XferMethod}) to actually restore the
files. Sorry, there is currently no option to cancel a restore
that has been started.
A record of the restore request, including the result and list of
files and directories, is kept. It can be browsed from the host's
home page. $Conf{RestoreInfoKeepCnt} specifies how many old
restore status files to keep.
Note that for direct restore to work, the $Conf{XferMethod} must be
able to write to the client. For example, that means an SMB share
for smbclient needs to be writable, and the rsyncd module needs
"read only" set to "false". This creates additional security
risks. If you only create read-only SMB shares (which is a good
idea), then the direct restore will fail. You can disable the
direct restore option by setting $Conf{SmbClientRestoreCmd},
$Conf{TarClientRestoreCmd} and $Conf{RsyncRestoreArgs} to undef.
Option 2: Download Zip archive
With this option a zip file containing the selected files and
directories is downloaded. The zip file can then be unpacked or
individual files extracted as necessary on the host machine. The
compression level can be specified. A value of 0 turns off
compression.
When you select "Download Zip File" you should be prompted where to
save the restore.zip file.
BackupPC does not consider downloading a zip file as an actual
restore operation, so the details are not saved for later browsing
as in the first case. However, a mention that a zip file was
downloaded by a particular user, and a list of the files, does
appear in BackupPC's log file.
Option 3: Download Tar archive
This is identical to the previous option, except a tar file is
downloaded rather than a zip file (and there is currently no
compression option).
Command-line restore options
Apart from the CGI interface, BackupPC allows you to restore files and
directories from the command line. The following programs can be used:
BackupPC_zcat
For each file name argument it inflates (uncompresses) the file and
writes it to stdout. To use BackupPC_zcat you could give it the
full file name, eg:
__INSTALLDIR__/bin/BackupPC_zcat __TOPDIR__/pc/host/5/fc/fcraig/fexample.txt > example.txt
It's your responsibility to make sure the file is really
compressed: BackupPC_zcat doesn't check which backup the requested
file is from. BackupPC_zcat returns a non-zero status if it fails
to uncompress a file.
BackupPC_tarCreate
BackupPC_tarCreate creates a tar file for any files or directories
in a particular backup. Merging of incrementals is done
automatically, so you don't need to worry about whether certain
files appear in the incremental or full backup.
The usage is:
BackupPC_tarCreate [options] files/directories...
Required options:
-h host host from which the tar archive is created
-n dumpNum dump number from which the tar archive is created
A negative number means relative to the end (eg -1
means the most recent dump, -2 2nd most recent etc).
-s shareName share name from which the tar archive is created
Other options:
-t print summary totals
-r pathRemove path prefix that will be replaced with pathAdd
-p pathAdd new path prefix
-b BLOCKS BLOCKS x 512 bytes per record (default 20; same as tar)
-w writeBufSz write buffer size (default 1048576 = 1MB)
-e charset charset for encoding file names (default: value of
$Conf{ClientCharset} when backup was done)
-l just print a file listing; don't generate an archive
-L just print a detailed file listing; don't generate an archive
The command-line files and directories are relative to the
specified shareName. The tar file is written to stdout.
The -h, -n and -s options specify which dump is used to generate
the tar archive. The -r and -p options can be used to relocate the
paths in the tar archive so extracted files can be placed in a
location different from their original location.
BackupPC_zipCreate
BackupPC_zipCreate creates a zip file for any files or directories
in a particular backup. Merging of incrementals is done
automatically, so you don't need to worry about whether certain
files appear in the incremental or full backup.
The usage is:
BackupPC_zipCreate [options] files/directories...
Required options:
-h host host from which the zip archive is created
-n dumpNum dump number from which the tar archive is created
A negative number means relative to the end (eg -1
means the most recent dump, -2 2nd most recent etc).
-s shareName share name from which the zip archive is created
Other options:
-t print summary totals
-r pathRemove path prefix that will be replaced with pathAdd
-p pathAdd new path prefix
-c level compression level (default is 0, no compression)
-e charset charset for encoding file names (default: cp1252)
The command-line files and directories are relative to the
specified shareName. The zip file is written to stdout. The -h, -n
and -s options specify which dump is used to generate the zip
archive. The -r and -p options can be used to relocate the paths
in the zip archive so extracted files can be placed in a location
different from their original location.
Each of these programs reside in __INSTALLDIR__/bin.
Archive functions
BackupPC supports archiving to removable media. For users that require
offsite backups, BackupPC can create archives that stream to tape
devices, or create files of specified sizes to fit onto cd or dvd
media.
Each archive type is specified by a BackupPC host with its XferMethod
set to 'archive'. This allows for multiple configurations at sites
where there might be a combination of tape and cd/dvd backups being
made.
BackupPC provides a menu that allows one or more hosts to be archived.
The most recent backup of each host is archived using
BackupPC_tarCreate, and the output is optionally compressed and split
into fixed-sized files (eg: 650MB).
The archive for each host is done by default using
__INSTALLDIR__/bin/BackupPC_archiveHost. This script can be copied and
customized as needed.
Configuring an Archive Host
To create an Archive Host, add it to the hosts file just as any other
host and call it a name that best describes the type of archive, e.g.
ArchiveDLT
To tell BackupPC that the Host is for Archives, create a config.pl file
in the Archive Hosts's pc directory, adding the following line:
$Conf{XferMethod} = 'archive';
To further customise the archive's parameters you can adding the
changed parameters in the host's config.pl file. The parameters are
explained in the config.pl file. Parameters may be fixed or the user
can be allowed to change them (eg: output device).
The per-host archive command is $Conf{ArchiveClientCmd}. By default
this invokes
__INSTALLDIR__/bin/BackupPC_archiveHost
which you can copy and customize as necessary.
Starting an Archive
In the web interface, click on the Archive Host you wish to use. You
will see a list of previous archives and a summary on each. By clicking
the "Start Archive" button you are presented with the list of hosts and
the approximate backup size (note this is raw size, not projected
compressed size) Select the hosts you wish to archive and press the
"Archive Selected Hosts" button.
The next screen allows you to adjust the parameters for this archive
run. Press the "Start the Archive" to start archiving the selected
hosts with the parameters displayed.
Starting an Archive from the command line
The script BackupPC_archiveStart can be used to start an archive from
the command line (or cron etc). The usage is:
BackupPC_archiveStart archiveHost userName hosts...
This creates an archive of the most recent backup of each of the
specified hosts. The first two arguments are the archive host and the
user name making the request.
Other CGI Functions
Configuration and Host Editor
The CGI interface has a complete configuration and host editor. Only
the administrator can edit the main configuration settings and hosts.
The edit links are in the left navigation bar.
When changes are made to any parameter a "Save" button appears at the
top of the page. If you are editing a text box you will need to click
outside of the text box to make the Save button appear. If you don't
select Save then the changes won't be saved.
The host-specific configuration can be edited from the host summary
page using the link in the left navigation bar. The administrator can
edit any of the host-specific configuration settings.
When editing the host-specific configuration, each parameter has an
"override" setting that denotes the value is host-specific, meaning
that it overrides the setting in the main configuration. If you
unselect "override" then the setting is removed from the host-specific
configuration, and the main configuration file is displayed.
User's can edit their host-specific configuration if enabled via
$Conf{CgiUserConfigEditEnable}. The specific subset of configuration
settings that a user can edit is specified with
$Conf{CgiUserConfigEdit}. It is recommended to make this list short as
possible (you probably don't want your users saving dozens of backups)
and it is essential that they can't edit any of the Cmd configuration
settings, otherwise they can specify an arbitrary command that will be
executed as the BackupPC user.
RSS
BackupPC supports a very basic RSS feed. Provided you have the
XML::RSS perl module installed, a URL similar to this will provide RSS
information:
http://localhost/cgi-bin/BackupPC/BackupPC_Admin?action=rss
This feature is experimental. The information included will probably
change.
BackupPC Design
Some design issues
Pooling common files
To quickly see if a file is already in the pool, an MD5 digest of
the file length and contents is used as the file name in the pool.
This can't guarantee a file is identical: it just reduces the
search to often a single file or handful of files. A complete file
comparison is always done to verify if two files are really the
same.
Identical files on multiples backups are represented by hard links.
Hardlinks are used so that identical files all refer to the same
physical file on the server's disk. Also, hard links maintain
reference counts so that BackupPC knows when to delete unused files
from the pool.
For the computer-science majors among you, you can think of the
pooling system used by BackupPC as just a chained hash table stored
on a (big) file system.
The hashing function
There is a tradeoff between how much of file is used for the MD5
digest and the time taken comparing all the files that have the
same hash.
Using the file length and just the first 4096 bytes of the file for
the MD5 digest produces some repetitions. One example: with
900,000 unique files in the pool, this hash gives about 7,000
repeated files, and in the worst case 500 files have the same hash.
That's not bad: we only have to do a single file compare 99.2% of
the time. But in the worst case we have to compare as many as 500
files checking for a match.
With a modest increase in CPU time, if we use the file length and
the first 256K of the file we now only have 500 repeated files and
in the worst case around 20 files have the same hash. Furthermore,
if we instead use the first and last 128K of the file (more
specifically, the first and eighth 128K chunks for files larger
than 1MB) we get only 300 repeated files and in the worst case
around 20 files have the same hash.
Based on this experimentation, this is the hash function used by
BackupPC. It is important that you don't change the hash function
after files are already in the pool. Otherwise your pool will grow
to twice the size until all the old backups (and all the old files
with old hashes) eventually expire.
Compression
BackupPC supports compression. It uses the deflate and inflate
methods in the Compress::Zlib module, which is based on the zlib
compression library (see <http://www.gzip.org/zlib/>).
The $Conf{CompressLevel} setting specifies the compression level to
use. Zero (0) means no compression. Compression levels can be from
1 (least cpu time, slightly worse compression) to 9 (most cpu time,
slightly better compression). The recommended value is 3. Changing
it to 5, for example, will take maybe 20% more cpu time and will
get another 2-3% additional compression. Diminishing returns set in
above 5. See the zlib documentation for more information about
compression levels.
BackupPC implements compression with minimal CPU load. Rather than
compressing every incoming backup file and then trying to match it
against the pool, BackupPC computes the MD5 digest based on the
uncompressed file, and matches against the candidate pool files by
comparing each uncompressed pool file against the incoming backup
file. Since inflating a file takes roughly a factor of 10 less CPU
time than deflating there is a big saving in CPU time.
The combination of pooling common files and compression can yield a
factor of 8 or more overall saving in backup storage.
BackupPC operation
BackupPC reads the configuration information from
__CONFDIR__/config.pl. It then runs and manages all the backup
activity. It maintains queues of pending backup requests, user backup
requests and administrative commands. Based on the configuration
various requests will be executed simultaneously.
As specified by $Conf{WakeupSchedule}, BackupPC wakes up periodically
to queue backups on all the PCs. This is a four step process:
1. For each host and DHCP address backup requests are queued on the
background command queue.
2. For each PC, BackupPC_dump is forked. Several of these may be run
in parallel, based on the configuration. First a ping is done to
see if the machine is alive. If this is a DHCP address, nmblookup
is run to get the netbios name, which is used as the host name. If
DNS lookup fails, $Conf{NmbLookupFindHostCmd} is run to find the IP
address from the host name. The file __TOPDIR__/pc/$host/backups
is read to decide whether a full or incremental backup needs to be
run. If no backup is scheduled, or the ping to $host fails, then
BackupPC_dump exits.
The backup is done using the specified XferMethod. Either samba's
smbclient or tar over ssh/rsh/nfs piped into BackupPC_tarExtract,
or rsync over ssh/rsh is run, or rsyncd is connected to, with the
incoming data extracted to __TOPDIR__/pc/$host/new. The XferMethod
output is put into __TOPDIR__/pc/$host/XferLOG.
The letter in the XferLOG file shows the type of object, similar to
the first letter of the modes displayed by ls -l:
d -> directory
l -> symbolic link
b -> block special file
c -> character special file
p -> pipe file (fifo)
nothing -> regular file
The words mean:
create
new for this backup (ie: directory or file not in pool)
pool
found a match in the pool
same
file is identical to previous backup (contents were checksummed
and verified during full dump).
skip
file skipped in incremental because attributes are the same
(only displayed if $Conf{XferLogLevel} >= 2).
As BackupPC_tarExtract extracts the files from smbclient or tar, or
as rsync runs, it checks each file in the backup to see if it is
identical to an existing file from any previous backup of any PC.
It does this without needed to write the file to disk. If the file
matches an existing file, a hardlink is created to the existing
file in the pool. If the file does not match any existing files,
the file is written to disk and the file name is saved in
__TOPDIR__/pc/$host/NewFileList for later processing by
BackupPC_link. BackupPC_tarExtract and rsync can handle
arbitrarily large files and multiple candidate matching files
without needing to write the file to disk in the case of a match.
This significantly reduces disk writes (and also reads, since the
pool file comparison is done disk to memory, rather than disk to
disk).
Based on the configuration settings, BackupPC_dump checks each old
backup to see if any should be removed. Any expired backups are
moved to __TOPDIR__/trash for later removal by BackupPC_trashClean.
3. For each complete, good, backup, BackupPC_link is run. To avoid
race conditions as new files are linked into the pool area, only a
single BackupPC_link program runs at a time and the rest are
queued.
BackupPC_link reads the NewFileList written by BackupPC_dump and
inspects each new file in the backup. It re-checks if there is a
matching file in the pool (another BackupPC_link could have added
the file since BackupPC_dump checked). If so, the file is removed
and replaced by a hard link to the existing file. If the file is
new, a hard link to the file is made in the pool area, so that this
file is available for checking against each new file and new
backup.
Then, if $Conf{IncrFill} is set (note that the default setting is
off), for each incremental backup, hard links are made in the new
backup to all files that were not extracted during the incremental
backups. The means the incremental backup looks like a complete
image of the PC (with the exception that files that were removed on
the PC since the last full backup will still appear in the backup
directory tree).
The CGI interface knows how to merge unfilled incremental backups
will the most recent prior filled (full) backup, giving the
incremental backups a filled appearance. The default for
$Conf{IncrFill} is off, since there is no need to fill incremental
backups. This saves some level of disk activity, since lots of
extra hardlinks are no longer needed (and don't have to be deleted
when the backup expires).
4. BackupPC_trashClean is always run in the background to remove any
expired backups. Every 5 minutes it wakes up and removes all the
files in __TOPDIR__/trash.
Also, once each night, BackupPC_nightly is run to complete some
additional administrative tasks, such as cleaning the pool. This
involves removing any files in the pool that only have a single
hard link (meaning no backups are using that file). Again, to
avoid race conditions, BackupPC_nightly is only run when there are
no BackupPC_link processes running. When BackupPC_nightly is run
no new BackupPC_link jobs are started. If BackupPC_nightly takes
too long to run, the settings $Conf{MaxBackupPCNightlyJobs} and
$Conf{BackupPCNightlyPeriod} can be used to run several
BackupPC_nightly processes in parallel, and to split its job over
several nights.
BackupPC also listens for TCP connections on $Conf{ServerPort}, which
is used by the CGI script BackupPC_Admin for status reporting and user-
initiated backup or backup cancel requests.
Storage layout
BackupPC resides in several directories:
__INSTALLDIR__
Perl scripts comprising BackupPC reside in __INSTALLDIR__/bin,
libraries are in __INSTALLDIR__/lib and documentation is in
__INSTALLDIR__/doc.
__CGIDIR__
The CGI script BackupPC_Admin resides in this cgi binary directory.
__CONFDIR__
All the configuration information resides below __CONFDIR__. This
directory contains:
The directory __CONFDIR__ contains:
config.pl
Configuration file. See Configuration file below for more
details.
hosts
Hosts file, which lists all the PCs to backup.
pc The directory __CONFDIR__/pc contains per-client configuration
files that override settings in the main configuration file.
Each file is named __CONFDIR__/pc/HOST.pl, where HOST is the
host name.
In pre-FHS versions of BackupPC these files were located in
__TOPDIR__/pc/HOST/config.pl.
__LOGDIR__
The directory __LOGDIR__ (__TOPDIR__/log on pre-FHS versions of
BackupPC) contains:
LOG Current (today's) log file output from BackupPC.
LOG.0 or LOG.0.z
Yesterday's log file output. Log files are aged daily and
compressed (if compression is enabled), and old LOG files are
deleted.
BackupPC.pid
Contains BackupPC's process id.
status.pl
A summary of BackupPC's status written periodically by BackupPC
so that certain state information can be maintained if BackupPC
is restarted. Should not be edited.
UserEmailInfo.pl
A summary of what email was last sent to each user, and when
the last email was sent. Should not be edited.
__TOPDIR__
All of BackupPC's data (PC backup images, logs, configuration
information) is stored below this directory.
Below __TOPDIR__ are several directories:
__TOPDIR__/trash
Any directories and files below this directory are periodically
deleted whenever BackupPC_trashClean checks. When a backup is
aborted or when an old backup expires, BackupPC_dump simply
moves the directory to __TOPDIR__/trash for later removal by
BackupPC_trashClean.
__TOPDIR__/pool
All uncompressed files from PC backups are stored below
__TOPDIR__/pool. Each file's name is based on the MD5 hex
digest of the file contents. Specifically, for files less than
256K, the file length and the entire file is used. For files up
to 1MB, the file length and the first and last 128K are used.
Finally, for files longer than 1MB, the file length, and the
first and eighth 128K chunks for the file are used.
Each file is stored in a subdirectory X/Y/Z, where X, Y, Z are
the first 3 hex digits of the MD5 digest.
For example, if a file has an MD5 digest of 123456789abcdef0,
the file is stored in __TOPDIR__/pool/1/2/3/123456789abcdef0.
The MD5 digest might not be unique (especially since not all
the file's contents are used for files bigger than 256K).
Different files that have the same MD5 digest are stored with a
trailing suffix "_n" where n is an incrementing number starting
at 0. So, for example, if two additional files were identical
to the first, except the last byte was different, and assuming
the file was larger than 1MB (so the MD5 digests are the same
but the files are actually different), the three files would be
stored as:
__TOPDIR__/pool/1/2/3/123456789abcdef0
__TOPDIR__/pool/1/2/3/123456789abcdef0_0
__TOPDIR__/pool/1/2/3/123456789abcdef0_1
Both BackupPC_dump (actually, BackupPC_tarExtract) and
BackupPC_link are responsible for checking newly backed up
files against the pool. For each file, the MD5 digest is used
to generate a file name in the pool directory. If the file
exists in the pool, the contents are compared. If there is no
match, additional files ending in "_n" are checked. (Actually,
BackupPC_tarExtract compares multiple candidate files in
parallel.) If the file contents exactly match, the file is
created by simply making a hard link to the pool file (this is
done by BackupPC_tarExtract as the backup proceeds). Otherwise,
BackupPC_tarExtract writes the new file to disk and a new hard
link is made in the pool to the file (this is done later by
BackupPC_link).
Therefore, every file in the pool will have at least 2 hard
links (one for the pool file and one for the backup file below
__TOPDIR__/pc). Identical files from different backups or PCs
will all be linked to the same file. When old backups are
deleted, some files in the pool might only have one link.
BackupPC_nightly checks the entire pool and removes all files
that have only a single link, thereby recovering the storage
for that file.
One other issue: zero length files are not pooled, since there
are a lot of these files and on most file systems it doesn't
save any disk space to turn these files into hard links.
__TOPDIR__/cpool
All compressed files from PC backups are stored below
__TOPDIR__/cpool. Its layout is the same as __TOPDIR__/pool,
and the hashing function is the same (and, importantly, based
on the uncompressed file, not the compressed file).
__TOPDIR__/pc/$host
For each PC $host, all the backups for that PC are stored below
the directory __TOPDIR__/pc/$host. This directory contains the
following files:
LOG Current log file for this PC from BackupPC_dump.
LOG.DDMMYYYY or LOG.DDMMYYYY.z
Last month's log file. Log files are aged monthly and
compressed (if compression is enabled), and old LOG files
are deleted. In earlier versions of BackupPC these files
used to have a suffix of 0, 1, ....
XferERR or XferERR.z
Output from the transport program (ie: smbclient, tar or
rsync) for the most recent failed backup.
new Subdirectory in which the current backup is stored. This
directory is renamed if the backup succeeds.
XferLOG or XferLOG.z
Output from the transport program (ie: smbclient, tar or
rsync) for the current backup.
nnn (an integer)
Successful backups are in directories numbered sequentially
starting at 0.
XferLOG.nnn or XferLOG.nnn.z
Output from the transport program (ie: smbclient, tar or
rsync) corresponding to backup number nnn.
RestoreInfo.nnn
Information about restore request #nnn including who, what,
when, and why. This file is in Data::Dumper format. (Note
that the restore numbers are not related to the backup
number.)
RestoreLOG.nnn.z
Output from smbclient, tar or rsync during restore #nnn.
(Note that the restore numbers are not related to the
backup number.)
ArchiveInfo.nnn
Information about archive request #nnn including who, what,
when, and why. This file is in Data::Dumper format. (Note
that the archive numbers are not related to the restore or
backup number.)
ArchiveLOG.nnn.z
Output from archive #nnn. (Note that the archive numbers
are not related to the backup or restore number.)
config.pl
Old location of optional configuration settings specific to
this host. Settings in this file override the main
configuration file. In new versions of BackupPC the per-
host configuration files are stored in
__CONFDIR__/pc/HOST.pl.
backups
A tab-delimited ascii table listing information about each
successful backup, one per row. The columns are:
num The backup number, an integer that starts at 0 and
increments for each successive backup. The
corresponding backup is stored in the directory num
(eg: if this field is 5, then the backup is stored in
__TOPDIR__/pc/$host/5).
type
Set to "full" or "incr" for full or incremental backup.
startTime
Start time of the backup in unix seconds.
endTime
Stop time of the backup in unix seconds.
nFiles
Number of files backed up (as reported by smbclient,
tar or rsync).
size
Total file size backed up (as reported by smbclient,
tar or rsync).
nFilesExist
Number of files that were already in the pool (as
determined by BackupPC_dump and BackupPC_link).
sizeExist
Total size of files that were already in the pool (as
determined by BackupPC_dump and BackupPC_link).
nFilesNew
Number of files that were not in the pool (as
determined by BackupPC_link).
sizeNew
Total size of files that were not in the pool (as
determined by BackupPC_link).
xferErrs
Number of errors or warnings from smbclient, tar or
rsync.
xferBadFile
Number of errors from smbclient that were bad file
errors (zero otherwise).
xferBadShare
Number of errors from smbclient that were bad share
errors (zero otherwise).
tarErrs
Number of errors from BackupPC_tarExtract.
compress
The compression level used on this backup. Zero or
empty means no compression.
sizeExistComp
Total compressed size of files that were already in the
pool (as determined by BackupPC_dump and
BackupPC_link).
sizeNewComp
Total compressed size of files that were not in the
pool (as determined by BackupPC_link).
noFill
Set if this backup has not been filled in with the most
recent previous filled or full backup. See
$Conf{IncrFill}.
fillFromNum
If this backup was filled (ie: noFill is 0) then this
is the number of the backup that it was filled from
mangle
Set if this backup has mangled file names and
attributes. Always true for backups in v1.4.0 and
above. False for all backups prior to v1.4.0.
xferMethod
Set to the value of $Conf{XferMethod} when this dump
was done.
level
The level of this dump. A full dump is level 0.
Currently incrementals are 1. But when multi-level
incrementals are supported this will reflect each
dump's incremental level.
restores
A tab-delimited ascii table listing information about each
requested restore, one per row. The columns are:
num Restore number (matches the suffix of the
RestoreInfo.nnn and RestoreLOG.nnn.z file), unrelated
to the backup number.
startTime
Start time of the restore in unix seconds.
endTime
End time of the restore in unix seconds.
result
Result (ok or failed).
errorMsg
Error message if restore failed.
nFiles
Number of files restored.
size
Size in bytes of the restored files.
tarCreateErrs
Number of errors from BackupPC_tarCreate during
restore.
xferErrs
Number of errors from smbclient, tar or rsync during
restore.
archives
A tab-delimited ascii table listing information about each
requested archive, one per row. The columns are:
num Archive number (matches the suffix of the
ArchiveInfo.nnn and ArchiveLOG.nnn.z file), unrelated
to the backup or restore number.
startTime
Start time of the restore in unix seconds.
endTime
End time of the restore in unix seconds.
result
Result (ok or failed).
errorMsg
Error message if archive failed.
Compressed file format
The compressed file format is as generated by Compress::Zlib::deflate
with one minor, but important, tweak. Since Compress::Zlib::inflate
fully inflates its argument in memory, it could take large amounts of
memory if it was inflating a highly compressed file. For example, a
200MB file of 0x0 bytes compresses to around 200K bytes. If
Compress::Zlib::inflate was called with this single 200K buffer, it
would need to allocate 200MB of memory to return the result.
BackupPC watches how efficiently a file is compressing. If a big file
has very high compression (meaning it will use too much memory when it
is inflated), BackupPC calls the flush() method, which gracefully
completes the current compression. BackupPC then starts another
deflate and simply appends the output file. So the BackupPC compressed
file format is one or more concatenated deflations/flushes. The
specific ratios that BackupPC uses is that if a 6MB chunk compresses to
less than 64K then a flush will be done.
Back to the example of the 200MB file of 0x0 bytes. Adding flushes
every 6MB adds only 200 or so bytes to the 200K output. So the storage
cost of flushing is negligible.
To easily decompress a BackupPC compressed file, the script
BackupPC_zcat can be found in __INSTALLDIR__/bin. For each file name
argument it inflates the file and writes it to stdout.
Rsync checksum caching
An incremental backup with rsync compares attributes on the client with
the last full backup. Any files with identical attributes are skipped.
A full backup with rsync sets the --ignore-times option, which causes
every file to be examined independent of attributes.
Each file is examined by generating block checksums (default 2K blocks)
on the receiving side (that's the BackupPC side), sending those
checksums to the client, where the remote rsync matches those checksums
with the corresponding file. The matching blocks and new data is sent
back, allowing the client file to be reassembled. A checksum for the
entire file is sent to as an extra check the the reconstructed file is
correct.
This results in significant disk IO and computation for BackupPC: every
file in a full backup, or any file with non-matching attributes in an
incremental backup, needs to be uncompressed, block checksums computed
and sent. Then the receiving side reassembles the file and has to
verify the whole-file checksum. Even if the file is identical, prior
to 2.1.0, BackupPC had to read and uncompress the file twice, once to
compute the block checksums and later to verify the whole-file
checksum.
Starting in 2.1.0, BackupPC supports optional checksum caching, which
means the block and file checksums only need to be computed once for
each file. This results in a significant performance improvement.
This only works for compressed pool files. It is enabled by adding
'--checksum-seed=32761',
to $Conf{RsyncArgs} and $Conf{RsyncRestoreArgs}.
Rsync versions prior to and including rsync-2.6.2 need a small patch to
add support for the --checksum-seed option. This patch is available in
the cygwin-rsyncd package at <http://backuppc.sourceforge.net>. This
patch is already included in rsync CVS, so it will be standard in
future versions of rsync.
When this option is present, BackupPC will add block and file checksums
to the compressed pool file the next time a pool file is used and it
doesn't already have cached checksums. The first time a new file is
written to the pool, the checksums are not appended. The next time
checksums are needed for a file, they are computed and added. So the
full performance benefit of checksum caching won't be noticed until the
third time a pool file is used (eg: the third full backup).
With checksum caching enabled, there is a risk that should a file's
contents in the pool be corrupted due to a disk problem, but the cached
checksums are still correct, the corruption will not be detected by a
full backup, since the file contents are no longer read and compared.
To reduce the chance that this remains undetected, BackupPC can recheck
cached checksums for a fraction of the files. This fraction is set
with the $Conf{RsyncCsumCacheVerifyProb} setting. The default value of
0.01 means that 1% of the time a file's checksums are read, the
checksums are verified. This reduces performance slightly, but, over
time, ensures that files contents are in sync with the cached
checksums.
The format of the cached checksum data can be discovered by looking at
the code. Basically, the first byte of the compressed file is changed
to denote that checksums are appended. The block and file checksum
data, plus some other information and magic word, are appended to the
compressed file. This allows the cache update to be done in-place.
File name mangling
Backup file names are stored in "mangled" form. Each node of a path is
preceded by "f" (mnemonic: file), and special characters (\n, \r, % and
/) are URI-encoded as "%xx", where xx is the ascii character's hex
value. So c:/craig/example.txt is now stored as
fc/fcraig/fexample.txt.
This was done mainly so meta-data could be stored alongside the backup
files without name collisions. In particular, the attributes for the
files in a directory are stored in a file called "attrib", and mangling
avoids file name collisions (I discarded the idea of having a duplicate
directory tree for every backup just to store the attributes). Other
meta-data (eg: rsync checksums) could be stored in file names preceded
by, eg, "c". There are two other benefits to mangling: the share name
might contain "/" (eg: "/home/craig" for tar transport), and I wanted
that represented as a single level in the storage tree. Secondly, as
files are written to NewFileList for later processing by BackupPC_link,
embedded newlines in the file's path will cause problems which are
avoided by mangling.
The CGI script undoes the mangling, so it is invisible to the user.
Old (unmangled) backups are still supported by the CGI interface.
Special files
Linux/unix file systems support several special file types: symbolic
links, character and block device files, fifos (pipes) and unix-domain
sockets. All except unix-domain sockets are supported by BackupPC
(there's no point in backing up or restoring unix-domain sockets since
they only have meaning after a process creates them). Symbolic links
are stored as a plain file whose contents are the contents of the link
(not the file it points to). This file is compressed and pooled like
any normal file. Character and block device files are also stored as
plain files, whose contents are two integers separated by a comma; the
numbers are the major and minor device number. These files are
compressed and pooled like any normal file. Fifo files are stored as
empty plain files (which are not pooled since they have zero size). In
all cases, the original file type is stored in the attrib file so it
can be correctly restored.
Hardlinks are also supported. When GNU tar first encounters a file
with more than one link (ie: hardlinks) it dumps it as a regular file.
When it sees the second and subsequent hardlinks to the same file, it
dumps just the hardlink information. BackupPC correctly recognizes
these hardlinks and stores them just like symlinks: a regular text file
whose contents is the path of the file linked to. The CGI script will
download the original file when you click on a hardlink.
Also, BackupPC_tarCreate has enough magic to re-create the hardlinks
dynamically based on whether or not the original file and hardlinks are
both included in the tar file. For example, imagine a/b/x is a
hardlink to a/c/y. If you use BackupPC_tarCreate to restore directory
a, then the tar file will include a/b/x as the original file and a/c/y
will be a hardlink to a/b/x. If, instead you restore a/c, then the tar
file will include a/c/y as the original file, not a hardlink.
Attribute file format
The unix attributes for the contents of a directory (all the files and
directories in that directory) are stored in a file called attrib.
There is a single attrib file for each directory in a backup. For
example, if c:/craig contains a single file c:/craig/example.txt, that
file would be stored as fc/fcraig/fexample.txt and there would be an
attribute file in fc/fcraig/attrib (and also fc/attrib and ./attrib).
The file fc/fcraig/attrib would contain a single entry containing the
attributes for fc/fcraig/fexample.txt.
The attrib file starts with a magic number, followed by the
concatenation of the following information for each file:
o File name length in perl's pack "w" format (variable length base
128).
o File name.
o The unix file type, mode, uid, gid and file size divided by 4GB and
file size modulo 4GB (type mode uid gid sizeDiv4GB sizeMod4GB), in
perl's pack "w" format (variable length base 128).
o The unix mtime (unix seconds) in perl's pack "N" format (32 bit
integer).
The attrib file is also compressed if compression is enabled. See the
lib/BackupPC/Attrib.pm module for full details.
Attribute files are pooled just like normal backup files. This saves
space if all the files in a directory have the same attributes across
multiple backups, which is common.
Optimizations
BackupPC doesn't care about the access time of files in the pool since
it saves attribute meta-data separate from the files. Since BackupPC
mostly does reads from disk, maintaining the access time of files
generates a lot of unnecessary disk writes. So, provided BackupPC has
a dedicated data disk, you should consider mounting BackupPC's data
directory with the noatime (or, with Linux kernels >=2.6.20, relatime)
attribute (see mount(1)).
Limitations
BackupPC isn't perfect (but it is getting better). Please see
<http://backuppc.sourceforge.net/faq/limitations.html> for a discussion
of some of BackupPC's limitations.
Security issues
Please see <http://backuppc.sourceforge.net/faq/security.html> for a
discussion of some of various security issues.
Configuration File
The BackupPC configuration file resides in __CONFDIR__/config.pl.
Optional per-PC configuration files reside in __CONFDIR__/pc/$host.pl
(or __TOPDIR__/pc/$host/config.pl in non-FHS versions of BackupPC).
This file can be used to override settings just for a particular PC.
Modifying the main configuration file
The configuration file is a perl script that is executed by BackupPC,
so you should be careful to preserve the file syntax (punctuation,
quotes etc) when you edit it. It is recommended that you use CVS, RCS
or some other method of source control for changing config.pl.
BackupPC reads or re-reads the main configuration file and the hosts
file in three cases:
o Upon startup.
o When BackupPC is sent a HUP (-1) signal. Assuming you installed
the init.d script, you can also do this with "/etc/init.d/backuppc
reload".
o When the modification time of config.pl file changes. BackupPC
checks the modification time once during each regular wakeup.
Whenever you change the configuration file you can either do a kill
-HUP BackupPC_pid or simply wait until the next regular wakeup period.
Each time the configuration file is re-read a message is reported in
the LOG file, so you can tail it (or view it via the CGI interface) to
make sure your kill -HUP worked. Errors in parsing the configuration
file are also reported in the LOG file.
The optional per-PC configuration file (__CONFDIR__/pc/$host.pl or
__TOPDIR__/pc/$host/config.pl in non-FHS versions of BackupPC) is read
whenever it is needed by BackupPC_dump, BackupPC_link and others.
Configuration Parameters
The configuration parameters are divided into five general groups. The
first group (general server configuration) provides general
configuration for BackupPC. The next two groups describe what to
backup, when to do it, and how long to keep it. The fourth group are
settings for email reminders, and the final group contains settings for
the CGI interface.
All configuration settings in the second through fifth groups can be
overridden by the per-PC config.pl file.
General server configuration
$Conf{ServerHost} = '';
Host name on which the BackupPC server is running.
$Conf{ServerPort} = -1;
TCP port number on which the BackupPC server listens for and
accepts connections. Normally this should be disabled (set to -1).
The TCP port is only needed if apache runs on a different machine
from BackupPC. In that case, set this to any spare port number
over 1024 (eg: 2359). If you enable the TCP port, make sure you
set $Conf{ServerMesgSecret} too!
$Conf{ServerMesgSecret} = '';
Shared secret to make the TCP port secure. Set this to a hard to
guess string if you enable the TCP port (ie: $Conf{ServerPort} >
0).
To avoid possible attacks via the TCP socket interface, every
client message is protected by an MD5 digest. The MD5 digest
includes four items:
- a seed that is sent to the client when the connection opens
- a sequence number that increments for each message
- a shared secret that is stored in $Conf{ServerMesgSecret}
- the message itself.
The message is sent in plain text preceded by the MD5 digest. A
snooper can see the plain-text seed sent by BackupPC and plain-text
message from the client, but cannot construct a valid MD5 digest
since the secret $Conf{ServerMesgSecret} is unknown. A replay
attack is not possible since the seed changes on a per-connection
and per-message basis.
$Conf{MyPath} = '/bin';
PATH setting for BackupPC. An explicit value is necessary for
taint mode. Value shouldn't matter too much since all execs use
explicit paths. However, taint mode in perl will complain if this
directory is world writable.
$Conf{UmaskMode} = 027;
Permission mask for directories and files created by BackupPC.
Default value prevents any access from group other, and prevents
group write.
$Conf{WakeupSchedule} = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23];
Times at which we wake up, check all the PCs, and schedule
necessary backups. Times are measured in hours since midnight.
Can be fractional if necessary (eg: 4.25 means 4:15am).
If the hosts you are backing up are always connected to the network
you might have only one or two wakeups each night. This will keep
the backup activity after hours. On the other hand, if you are
backing up laptops that are only intermittently connected to the
network you will want to have frequent wakeups (eg: hourly) to
maximize the chance that each laptop is backed up.
Examples:
$Conf{WakeupSchedule} = [22.5]; # once per day at 10:30 pm.
$Conf{WakeupSchedule} = [2,4,6,8,10,12,14,16,18,20,22]; # every 2 hours
The default value is every hour except midnight.
The first entry of $Conf{WakeupSchedule} is when BackupPC_nightly
is run. You might want to re-arrange the entries in
$Conf{WakeupSchedule} (they don't have to be ascending) so that the
first entry is when you want BackupPC_nightly to run (eg: when you
don't expect a lot of regular backups to run).
$Conf{MaxBackups} = 4;
Maximum number of simultaneous backups to run. If there are no
user backup requests then this is the maximum number of
simultaneous backups.
$Conf{MaxUserBackups} = 4;
Additional number of simultaneous backups that users can run. As
many as $Conf{MaxBackups} + $Conf{MaxUserBackups} requests can run
at the same time.
$Conf{MaxPendingCmds} = 10;
Maximum number of pending link commands. New backups will only be
started if there are no more than $Conf{MaxPendingCmds} plus
$Conf{MaxBackups} number of pending link commands, plus running
jobs. This limit is to make sure BackupPC doesn't fall too far
behind in running BackupPC_link commands.
$Conf{MaxBackupPCNightlyJobs} = 2;
How many BackupPC_nightly processes to run in parallel.
Each night, at the first wakeup listed in $Conf{WakeupSchedule},
BackupPC_nightly is run. Its job is to remove unneeded files in
the pool, ie: files that only have one link. To avoid race
conditions, BackupPC_nightly and BackupPC_link cannot run at the
same time. Starting in v3.0.0, BackupPC_nightly can run
concurrently with backups (BackupPC_dump).
So to reduce the elapsed time, you might want to increase this
setting to run several BackupPC_nightly processes in parallel (eg:
4, or even 8).
$Conf{BackupPCNightlyPeriod} = 1;
How many days (runs) it takes BackupPC_nightly to traverse the
entire pool. Normally this is 1, which means every night it runs,
it does traverse the entire pool removing unused pool files.
Other valid values are 2, 4, 8, 16. This causes BackupPC_nightly
to traverse 1/2, 1/4, 1/8 or 1/16th of the pool each night, meaning
it takes 2, 4, 8 or 16 days to completely traverse the pool. The
advantage is that each night the running time of BackupPC_nightly
is reduced roughly in proportion, since the total job is split over
multiple days. The disadvantage is that unused pool files take
longer to get deleted, which will slightly increase disk usage.
Note that even when $Conf{BackupPCNightlyPeriod} > 1,
BackupPC_nightly still runs every night. It just does less work
each time it runs.
Examples:
$Conf{BackupPCNightlyPeriod} = 1; # entire pool is checked every night
$Conf{BackupPCNightlyPeriod} = 2; # two days to complete pool check
# (different half each night)
$Conf{BackupPCNightlyPeriod} = 4; # four days to complete pool check
# (different quarter each night)
$Conf{MaxOldLogFiles} = 14;
Maximum number of log files we keep around in log directory. These
files are aged nightly. A setting of 14 means the log directory
will contain about 2 weeks of old log files, in particular at most
the files LOG, LOG.0, LOG.1, ... LOG.13 (except today's LOG, these
files will have a .z extension if compression is on).
If you decrease this number after BackupPC has been running for a
while you will have to manually remove the older log files.
$Conf{DfPath} = '';
Full path to the df command. Security caution: normal users should
not allowed to write to this file or directory.
$Conf{DfCmd} = '$dfPath $topDir';
Command to run df. The following variables are substituted at run-
time:
$dfPath path to df ($Conf{DfPath})
$topDir top-level BackupPC data directory
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{SplitPath} = '';
$Conf{ParPath} = '';
$Conf{CatPath} = '';
$Conf{GzipPath} = '';
$Conf{Bzip2Path} = '';
Full path to various commands for archiving
$Conf{DfMaxUsagePct} = 95;
Maximum threshold for disk utilization on the __TOPDIR__
filesystem. If the output from $Conf{DfPath} reports a percentage
larger than this number then no new regularly scheduled backups
will be run. However, user requested backups (which are usually
incremental and tend to be small) are still performed, independent
of disk usage. Also, currently running backups will not be
terminated when the disk usage exceeds this number.
$Conf{TrashCleanSleepSec} = 300;
How long BackupPC_trashClean sleeps in seconds between each check
of the trash directory. Once every 5 minutes should be reasonable.
$Conf{DHCPAddressRanges} = [];
List of DHCP address ranges we search looking for PCs to backup.
This is an array of hashes for each class C address range. This is
only needed if hosts in the conf/hosts file have the dhcp flag set.
Examples:
# to specify 192.10.10.20 to 192.10.10.250 as the DHCP address pool
$Conf{DHCPAddressRanges} = [
{
ipAddrBase => '192.10.10',
first => 20,
last => 250,
},
];
# to specify two pools (192.10.10.20-250 and 192.10.11.10-50)
$Conf{DHCPAddressRanges} = [
{
ipAddrBase => '192.10.10',
first => 20,
last => 250,
},
{
ipAddrBase => '192.10.11',
first => 10,
last => 50,
},
];
$Conf{BackupPCUser} = '';
The BackupPC user.
$Conf{TopDir} = '';
$Conf{ConfDir} = '';
$Conf{LogDir} = '';
$Conf{InstallDir} = '';
$Conf{CgiDir} = '';
Important installation directories:
TopDir - where all the backup data is stored
ConfDir - where the main config and hosts files resides
LogDir - where log files and other transient information
InstallDir - where the bin, lib and doc installation dirs reside.
Note: you cannot change this value since all the
perl scripts include this path. You must reinstall
with configure.pl to change InstallDir.
CgiDir - Apache CGI directory for BackupPC_Admin
$Conf{BackupPCUserVerify} = 1;
Whether BackupPC and the CGI script BackupPC_Admin verify that they
are really running as user $Conf{BackupPCUser}. If this flag is
set and the effective user id (euid) differs from
$Conf{BackupPCUser} then both scripts exit with an error. This
catches cases where BackupPC might be accidently started as root or
the wrong user, or if the CGI script is not installed correctly.
$Conf{HardLinkMax} = 31999;
Maximum number of hardlinks supported by the $TopDir file system
that BackupPC uses. Most linux or unix file systems should support
at least 32000 hardlinks per file, or 64000 in other cases. If a
pool file already has this number of hardlinks, a new pool file is
created so that new hardlinks can be accommodated. This limit will
only be hit if an identical file appears at least this number of
times across all the backups.
$Conf{PerlModuleLoad} = undef;
Advanced option for asking BackupPC to load additional perl
modules. Can be a list (array ref) of module names to load at
startup.
$Conf{ServerInitdPath} = '';
$Conf{ServerInitdStartCmd} = '';
Path to init.d script and command to use that script to start the
server from the CGI interface. The following variables are
substituted at run-time:
$sshPath path to ssh ($Conf{SshPath})
$serverHost same as $Conf{ServerHost}
$serverInitdPath path to init.d script ($Conf{ServerInitdPath})
Example:
$Conf{ServerInitdPath} = '/etc/init.d/backuppc';
$Conf{ServerInitdStartCmd} = '$sshPath -q -x -l root $serverHost'
. ' $serverInitdPath start'
. ' < /dev/null >& /dev/null';
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
What to backup and when to do it
$Conf{FullPeriod} = 6.97;
Minimum period in days between full backups. A full dump will only
be done if at least this much time has elapsed since the last full
dump, and at least $Conf{IncrPeriod} days has elapsed since the
last successful dump.
Typically this is set slightly less than an integer number of days.
The time taken for the backup, plus the granularity of
$Conf{WakeupSchedule} will make the actual backup interval a bit
longer.
$Conf{IncrPeriod} = 0.97;
Minimum period in days between incremental backups (a user
requested incremental backup will be done anytime on demand).
Typically this is set slightly less than an integer number of days.
The time taken for the backup, plus the granularity of
$Conf{WakeupSchedule} will make the actual backup interval a bit
longer.
$Conf{FullKeepCnt} = 1;
Number of full backups to keep. Must be >= 1.
In the steady state, each time a full backup completes successfully
the oldest one is removed. If this number is decreased, the extra
old backups will be removed.
If filling of incremental dumps is off the oldest backup always has
to be a full (ie: filled) dump. This might mean one or two extra
full dumps are kept until the oldest incremental backups expire.
Exponential backup expiry is also supported. This allows you to
specify:
- num fulls to keep at intervals of 1 * $Conf{FullPeriod}, followed by
- num fulls to keep at intervals of 2 * $Conf{FullPeriod},
- num fulls to keep at intervals of 4 * $Conf{FullPeriod},
- num fulls to keep at intervals of 8 * $Conf{FullPeriod},
- num fulls to keep at intervals of 16 * $Conf{FullPeriod},
and so on. This works by deleting every other full as each expiry
boundary is crossed.
Exponential expiry is specified using an array for
$Conf{FullKeepCnt}:
$Conf{FullKeepCnt} = [4, 2, 3];
Entry #n specifies how many fulls to keep at an interval of 2^n *
$Conf{FullPeriod} (ie: 1, 2, 4, 8, 16, 32, ...).
The example above specifies keeping 4 of the most recent full
backups (1 week interval) two full backups at 2 week intervals, and
3 full backups at 4 week intervals, eg:
full 0 19 weeks old \
full 1 15 weeks old >--- 3 backups at 4 * $Conf{FullPeriod}
full 2 11 weeks old /
full 3 7 weeks old \____ 2 backups at 2 * $Conf{FullPeriod}
full 4 5 weeks old /
full 5 3 weeks old \
full 6 2 weeks old \___ 4 backups at 1 * $Conf{FullPeriod}
full 7 1 week old /
full 8 current /
On a given week the spacing might be less than shown as each backup
ages through each expiry period. For example, one week later, a
new full is completed and the oldest is deleted, giving:
full 0 16 weeks old \
full 1 12 weeks old >--- 3 backups at 4 * $Conf{FullPeriod}
full 2 8 weeks old /
full 3 6 weeks old \____ 2 backups at 2 * $Conf{FullPeriod}
full 4 4 weeks old /
full 5 3 weeks old \
full 6 2 weeks old \___ 4 backups at 1 * $Conf{FullPeriod}
full 7 1 week old /
full 8 current /
You can specify 0 as a count (except in the first entry), and the
array can be as long as you wish. For example:
$Conf{FullKeepCnt} = [4, 0, 4, 0, 0, 2];
This will keep 10 full dumps, 4 most recent at 1 *
$Conf{FullPeriod}, followed by 4 at an interval of 4 *
$Conf{FullPeriod} (approx 1 month apart), and then 2 at an interval
of 32 * $Conf{FullPeriod} (approx 7-8 months apart).
Example: these two settings are equivalent and both keep just the
four most recent full dumps:
$Conf{FullKeepCnt} = 4;
$Conf{FullKeepCnt} = [4];
$Conf{FullKeepCntMin} = 1;
$Conf{FullAgeMax} = 90;
Very old full backups are removed after $Conf{FullAgeMax} days.
However, we keep at least $Conf{FullKeepCntMin} full backups no
matter how old they are.
Note that $Conf{FullAgeMax} will be increased to $Conf{FullKeepCnt}
times $Conf{FullPeriod} if $Conf{FullKeepCnt} specifies enough full
backups to exceed $Conf{FullAgeMax}.
$Conf{IncrKeepCnt} = 6;
Number of incremental backups to keep. Must be >= 1.
In the steady state, each time an incr backup completes
successfully the oldest one is removed. If this number is
decreased, the extra old backups will be removed.
$Conf{IncrKeepCntMin} = 1;
$Conf{IncrAgeMax} = 30;
Very old incremental backups are removed after $Conf{IncrAgeMax}
days. However, we keep at least $Conf{IncrKeepCntMin} incremental
backups no matter how old they are.
$Conf{IncrLevels} = [1];
Level of each incremental. "Level" follows the terminology of
dump(1). A full backup has level 0. A new incremental of level N
will backup all files that have changed since the most recent
backup of a lower level.
The entries of $Conf{IncrLevels} apply in order to each incremental
after each full backup. It wraps around until the next full
backup. For example, these two settings have the same effect:
$Conf{IncrLevels} = [1, 2, 3];
$Conf{IncrLevels} = [1, 2, 3, 1, 2, 3];
This means the 1st and 4th incrementals (level 1) go all the way
back to the full. The 2nd and 3rd (and 5th and 6th) backups just
go back to the immediate preceeding incremental.
Specifying a sequence of multi-level incrementals will usually mean
more than $Conf{IncrKeepCnt} incrementals will need to be kept,
since lower level incrementals are needed to merge a complete view
of a backup. For example, with
$Conf{FullPeriod} = 7;
$Conf{IncrPeriod} = 1;
$Conf{IncrKeepCnt} = 6;
$Conf{IncrLevels} = [1, 2, 3, 4, 5, 6];
there will be up to 11 incrementals in this case:
backup #0 (full, level 0, oldest)
backup #1 (incr, level 1)
backup #2 (incr, level 2)
backup #3 (incr, level 3)
backup #4 (incr, level 4)
backup #5 (incr, level 5)
backup #6 (incr, level 6)
backup #7 (full, level 0)
backup #8 (incr, level 1)
backup #9 (incr, level 2)
backup #10 (incr, level 3)
backup #11 (incr, level 4)
backup #12 (incr, level 5, newest)
Backup #1 (the oldest level 1 incremental) can't be deleted since
backups 2..6 depend on it. Those 6 incrementals can't all be
deleted since that would only leave 5 (#8..12). When the next
incremental happens (level 6), the complete set of 6 older
incrementals (#1..6) will be deleted, since that maintains the
required number ($Conf{IncrKeepCnt}) of incrementals. This
situation is reduced if you set shorter chains of multi-level
incrementals, eg:
$Conf{IncrLevels} = [1, 2, 3];
would only have up to 2 extra incremenals before all 3 are deleted.
BackupPC as usual merges the full and the sequence of incrementals
together so each incremental can be browsed and restored as though
it is a complete backup. If you specify a long chain of
incrementals then more backups need to be merged when browsing,
restoring, or getting the starting point for rsync backups. In the
example above (levels 1..6), browing backup #6 requires 7 different
backups (#0..6) to be merged.
Because of this merging and the additional incrementals that need
to be kept, it is recommended that some level 1 incrementals be
included in $Conf{IncrLevels}.
Prior to version 3.0 incrementals were always level 1, meaning each
incremental backed up all the files that changed since the last
full.
$Conf{BackupsDisable} = 0;
Disable all full and incremental backups. These settings are
useful for a client that is no longer being backed up (eg: a
retired machine), but you wish to keep the last backups available
for browsing or restoring to other machines.
There are three values for $Conf{BackupsDisable}:
0 Backups are enabled.
1 Don't do any regular backups on this client. Manually
requested backups (via the CGI interface) will still occur.
2 Don't do any backups on this client. Manually requested
backups (via the CGI interface) will be ignored.
In versions prior to 3.0 Backups were disabled by setting
$Conf{FullPeriod} to -1 or -2.
$Conf{PartialAgeMax} = 3;
A failed full backup is saved as a partial backup. The rsync
XferMethod can take advantage of the partial full when the next
backup is run. This parameter sets the age of the partial full in
days: if the partial backup is older than this number of days, then
rsync will ignore (not use) the partial full when the next backup
is run. If you set this to a negative value then no partials will
be saved. If you set this to 0, partials will be saved, but will
not be used by the next backup.
The default setting of 3 days means that a partial older than 3
days is ignored when the next full backup is done.
$Conf{IncrFill} = 0;
Whether incremental backups are filled. "Filling" means that the
most recent full (or filled) dump is merged into the new
incremental dump using hardlinks. This makes an incremental dump
look like a full dump. Prior to v1.03 all incremental backups were
filled. In v1.4.0 and later the default is off.
BackupPC, and the cgi interface in particular, do the right thing
on un-filled incremental backups. It will correctly display the
merged incremental backup with the most recent filled backup,
giving the un-filled incremental backups a filled appearance. That
means it invisible to the user whether incremental dumps are filled
or not.
Filling backups takes a little extra disk space, and it does cost
some extra disk activity for filling, and later removal. Filling
is no longer useful, since file mangling and compression doesn't
make a filled backup very useful. It's likely the filling option
will be removed from future versions: filling will be delegated to
the display and extraction of backup data.
If filling is off, BackupPC makes sure that the oldest backup is a
full, otherwise the following incremental backups will be
incomplete. This might mean an extra full backup has to be kept
until the following incremental backups expire.
The default is off. You can turn this on or off at any time
without affecting existing backups.
$Conf{RestoreInfoKeepCnt} = 10;
Number of restore logs to keep. BackupPC remembers information
about each restore request. This number per client will be kept
around before the oldest ones are pruned.
Note: files/dirs delivered via Zip or Tar downloads don't count as
restores. Only the first restore option (where the files and dirs
are written to the host) count as restores that are logged.
$Conf{ArchiveInfoKeepCnt} = 10;
Number of archive logs to keep. BackupPC remembers information
about each archive request. This number per archive client will be
kept around before the oldest ones are pruned.
$Conf{BackupFilesOnly} = undef;
List of directories or files to backup. If this is defined, only
these directories or files will be backed up.
For Smb, only one of $Conf{BackupFilesExclude} and
$Conf{BackupFilesOnly} can be specified per share. If both are set
for a particular share, then $Conf{BackupFilesOnly} takes
precedence and $Conf{BackupFilesExclude} is ignored.
This can be set to a string, an array of strings, or, in the case
of multiple shares, a hash of strings or arrays. A hash is used to
give a list of directories or files to backup for each share (the
share name is the key). If this is set to just a string or array,
and $Conf{SmbShareName} contains multiple share names, then the
setting is assumed to apply all shares.
If a hash is used, a special key "*" means it applies to all shares
that don't have a specific entry.
Examples:
$Conf{BackupFilesOnly} = '/myFiles';
$Conf{BackupFilesOnly} = ['/myFiles']; # same as first example
$Conf{BackupFilesOnly} = ['/myFiles', '/important'];
$Conf{BackupFilesOnly} = {
'c' => ['/myFiles', '/important'], # these are for 'c' share
'd' => ['/moreFiles', '/archive'], # these are for 'd' share
};
$Conf{BackupFilesOnly} = {
'c' => ['/myFiles', '/important'], # these are for 'c' share
'*' => ['/myFiles', '/important'], # these are other shares
};
$Conf{BackupFilesExclude} = undef;
List of directories or files to exclude from the backup. For Smb,
only one of $Conf{BackupFilesExclude} and $Conf{BackupFilesOnly}
can be specified per share. If both are set for a particular
share, then $Conf{BackupFilesOnly} takes precedence and
$Conf{BackupFilesExclude} is ignored.
This can be set to a string, an array of strings, or, in the case
of multiple shares, a hash of strings or arrays. A hash is used to
give a list of directories or files to exclude for each share (the
share name is the key). If this is set to just a string or array,
and $Conf{SmbShareName} contains multiple share names, then the
setting is assumed to apply to all shares.
The exact behavior is determined by the underlying transport
program, smbclient or tar. For smbclient the exlclude file list is
passed into the X option. Simple shell wild-cards using "*" or "?"
are allowed.
For tar, if the exclude file contains a "/" it is assumed to be
anchored at the start of the string. Since all the tar paths start
with "./", BackupPC prepends a "." if the exclude file starts with
a "/". Note that GNU tar version >= 1.13.7 is required for the
exclude option to work correctly. For linux or unix machines you
should add "/proc" to $Conf{BackupFilesExclude} unless you have
specified --one-file-system in $Conf{TarClientCmd} or
--one-file-system in $Conf{RsyncArgs}. Also, for tar, do not use a
trailing "/" in the directory name: a trailing "/" causes the name
to not match and the directory will not be excluded.
Users report that for smbclient you should specify a directory
followed by "/*", eg: "/proc/*", instead of just "/proc".
If a hash is used, a special key "*" means it applies to all shares
that don't have a specific entry.
Examples:
$Conf{BackupFilesExclude} = '/temp';
$Conf{BackupFilesExclude} = ['/temp']; # same as first example
$Conf{BackupFilesExclude} = ['/temp', '/winnt/tmp'];
$Conf{BackupFilesExclude} = {
'c' => ['/temp', '/winnt/tmp'], # these are for 'c' share
'd' => ['/junk', '/dont_back_this_up'], # these are for 'd' share
};
$Conf{BackupFilesExclude} = {
'c' => ['/temp', '/winnt/tmp'], # these are for 'c' share
'*' => ['/junk', '/dont_back_this_up'], # these are for other shares
};
$Conf{BlackoutBadPingLimit} = 3;
$Conf{BlackoutGoodCnt} = 7;
PCs that are always or often on the network can be backed up after
hours, to reduce PC, network and server load during working hours.
For each PC a count of consecutive good pings is maintained. Once a
PC has at least $Conf{BlackoutGoodCnt} consecutive good pings it is
subject to "blackout" and not backed up during hours and days
specified by $Conf{BlackoutPeriods}.
To allow for periodic rebooting of a PC or other brief periods when
a PC is not on the network, a number of consecutive bad pings is
allowed before the good ping count is reset. This parameter is
$Conf{BlackoutBadPingLimit}.
Note that bad and good pings don't occur with the same interval. If
a machine is always on the network, it will only be pinged roughly
once every $Conf{IncrPeriod} (eg: once per day). So a setting for
$Conf{BlackoutGoodCnt} of 7 means it will take around 7 days for a
machine to be subject to blackout. On the other hand, if a ping is
failed, it will be retried roughly every time BackupPC wakes up,
eg, every one or two hours. So a setting for
$Conf{BlackoutBadPingLimit} of 3 means that the PC will lose its
blackout status after 3-6 hours of unavailability.
To disable the blackout feature set $Conf{BlackoutGoodCnt} to a
negative value. A value of 0 will make all machines subject to
blackout. But if you don't want to do any backups during the day
it would be easier to just set $Conf{WakeupSchedule} to a
restricted schedule.
$Conf{BlackoutPeriods} = [ ... ];
One or more blackout periods can be specified. If a client is
subject to blackout then no regular (non-manual) backups will be
started during any of these periods. hourBegin and hourEnd specify
hours fro midnight and weekDays is a list of days of the week where
0 is Sunday, 1 is Monday etc.
For example:
$Conf{BlackoutPeriods} = [
{
hourBegin => 7.0,
hourEnd => 19.5,
weekDays => [1, 2, 3, 4, 5],
},
];
specifies one blackout period from 7:00am to 7:30pm local time on
Mon-Fri.
The blackout period can also span midnight by setting hourBegin >
hourEnd, eg:
$Conf{BlackoutPeriods} = [
{
hourBegin => 7.0,
hourEnd => 19.5,
weekDays => [1, 2, 3, 4, 5],
},
{
hourBegin => 23,
hourEnd => 5,
weekDays => [5, 6],
},
];
This specifies one blackout period from 7:00am to 7:30pm local time
on Mon-Fri, and a second period from 11pm to 5am on Friday and
Saturday night.
$Conf{BackupZeroFilesIsFatal} = 1;
A backup of a share that has zero files is considered fatal. This
is used to catch miscellaneous Xfer errors that result in no files
being backed up. If you have shares that might be empty (and
therefore an empty backup is valid) you should set this flag to 0.
How to backup a client
$Conf{XferMethod} = 'smb';
What transport method to use to backup each host. If you have a
mixed set of WinXX and linux/unix hosts you will need to override
this in the per-PC config.pl.
The valid values are:
- 'smb': backup and restore via smbclient and the SMB protocol.
Easiest choice for WinXX.
- 'rsync': backup and restore via rsync (via rsh or ssh).
Best choice for linux/unix. Good choice also for WinXX.
- 'rsyncd': backup and restore via rsync daemon on the client.
Best choice for linux/unix if you have rsyncd running on
the client. Good choice also for WinXX.
- 'tar': backup and restore via tar, tar over ssh, rsh or nfs.
Good choice for linux/unix.
- 'archive': host is a special archive host. Backups are not done.
An archive host is used to archive other host's backups
to permanent media, such as tape, CDR or DVD.
$Conf{XferLogLevel} = 1;
Level of verbosity in Xfer log files. 0 means be quiet, 1 will
give will give one line per file, 2 will also show skipped files on
incrementals, higher values give more output.
$Conf{ClientCharset} = '';
Filename charset encoding on the client. BackupPC uses utf8 on the
server for filename encoding. If this is empty, then utf8 is
assumed and client filenames will not be modified. If set to a
different encoding then filenames will converted to/from utf8
automatically during backup and restore.
If the file names displayed in the browser (eg: accents or special
characters) don't look right then it is likely you haven't set
$Conf{ClientCharset} correctly.
If you are using smbclient on a WinXX machine, smbclient will
convert to the "unix charset" setting in smb.conf. The default is
utf8, in which case leave $Conf{ClientCharset} empty since
smbclient does the right conversion.
If you are using rsync on a WinXX machine then it does no
conversion. A typical WinXX encoding for latin1/western europe is
'cp1252', so in this case set $Conf{ClientCharset} to 'cp1252'.
On a linux or unix client, run "locale charmap" to see the client's
charset. Set $Conf{ClientCharset} to this value. A typical value
for english/US is 'ISO-8859-1'.
Do "perldoc Encode::Supported" to see the list of possible charset
values. The FAQ at http://www.cl.cam.ac.uk/~mgk25/unicode.html is
excellent, and http://czyborra.com/charsets/iso88.html provides
more information on the iso-8859 charsets.
$Conf{ClientCharsetLegacy} = 'iso-8859-1';
Prior to 3.x no charset conversion was done by BackupPC. Backups
were stored in what ever charset the XferMethod provided -
typically utf8 for smbclient and the client's locale settings for
rsync and tar (eg: cp1252 for rsync on WinXX and perhaps iso-8859-1
with rsync on linux). This setting tells BackupPC the charset that
was used to store file names in old backups taken with BackupPC
2.x, so that non-ascii file names in old backups can be viewed and
restored.
$Conf{SmbShareName} = 'C$';
Name of the host share that is backed up when using SMB. This can
be a string or an array of strings if there are multiple shares per
host. Examples:
$Conf{SmbShareName} = 'c'; # backup 'c' share
$Conf{SmbShareName} = ['c', 'd']; # backup 'c' and 'd' shares
This setting only matters if $Conf{XferMethod} = 'smb'.
$Conf{SmbShareUserName} = '';
Smbclient share user name. This is passed to smbclient's -U
argument.
This setting only matters if $Conf{XferMethod} = 'smb'.
$Conf{SmbSharePasswd} = '';
Smbclient share password. This is passed to smbclient via its
PASSWD environment variable. There are several ways you can tell
BackupPC the smb share password. In each case you should be very
careful about security. If you put the password here, make sure
that this file is not readable by regular users! See the "Setting
up config.pl" section in the documentation for more information.
This setting only matters if $Conf{XferMethod} = 'smb'.
$Conf{SmbClientPath} = '';
Full path for smbclient. Security caution: normal users should not
allowed to write to this file or directory.
smbclient is from the Samba distribution. smbclient is used to
actually extract the incremental or full dump of the share
filesystem from the PC.
This setting only matters if $Conf{XferMethod} = 'smb'.
$Conf{SmbClientFullCmd} = '$smbClientPath \\\\$host\\$shareName' ...
Command to run smbclient for a full dump. This setting only
matters if $Conf{XferMethod} = 'smb'.
The following variables are substituted at run-time:
$smbClientPath same as $Conf{SmbClientPath}
$host host to backup/restore
$hostIP host IP address
$shareName share name
$userName user name
$fileList list of files to backup (based on exclude/include)
$I_option optional -I option to smbclient
$X_option exclude option (if $fileList is an exclude list)
$timeStampFile start time for incremental dump
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{SmbClientIncrCmd} = '$smbClientPath \\\\$host\\$shareName' ...
Command to run smbclient for an incremental dump. This setting
only matters if $Conf{XferMethod} = 'smb'.
Same variable substitutions are applied as $Conf{SmbClientFullCmd}.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{SmbClientRestoreCmd} = '$smbClientPath \\\\$host\\$shareName' ...
Command to run smbclient for a restore. This setting only matters
if $Conf{XferMethod} = 'smb'.
Same variable substitutions are applied as $Conf{SmbClientFullCmd}.
If your smb share is read-only then direct restores will fail. You
should set $Conf{SmbClientRestoreCmd} to undef and the
corresponding CGI restore option will be removed.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{TarShareName} = '/';
Which host directories to backup when using tar transport. This
can be a string or an array of strings if there are multiple
directories to backup per host. Examples:
$Conf{TarShareName} = '/'; # backup everything
$Conf{TarShareName} = '/home'; # only backup /home
$Conf{TarShareName} = ['/home', '/src']; # backup /home and /src
The fact this parameter is called 'TarShareName' is for historical
consistency with the Smb transport options. You can use any valid
directory on the client: there is no need for it to correspond to
any Smb share or device mount point.
Note also that you can also use $Conf{BackupFilesOnly} to specify a
specific list of directories to backup. It's more efficient to use
this option instead of $Conf{TarShareName} since a new tar is run
for each entry in $Conf{TarShareName}.
On the other hand, if you add --one-file-system to
$Conf{TarClientCmd} you can backup each file system separately,
which makes restoring one bad file system easier. In this case you
would list all of the mount points here, since you can't get the
same result with $Conf{BackupFilesOnly}:
$Conf{TarShareName} = ['/', '/var', '/data', '/boot'];
This setting only matters if $Conf{XferMethod} = 'tar'.
$Conf{TarClientCmd} = '$sshPath -q -x -n -l root $host' ...
Full command to run tar on the client. GNU tar is required. You
will need to fill in the correct paths for ssh2 on the local host
(server) and GNU tar on the client. Security caution: normal users
should not allowed to write to these executable files or
directories.
See the documentation for more information about setting up ssh2
keys.
If you plan to use NFS then tar just runs locally and ssh2 is not
needed. For example, assuming the client filesystem is mounted
below /mnt/hostName, you could use something like:
$Conf{TarClientCmd} = '$tarPath -c -v -f - -C /mnt/$host/$shareName'
. ' --totals';
In the case of NFS or rsh you need to make sure BackupPC's
privileges are sufficient to read all the files you want to backup.
Also, you will probably want to add "/proc" to
$Conf{BackupFilesExclude}.
The following variables are substituted at run-time:
$host host name
$hostIP host's IP address
$incrDate newer-than date for incremental backups
$shareName share name to backup (ie: top-level directory path)
$fileList specific files to backup or exclude
$tarPath same as $Conf{TarClientPath}
$sshPath same as $Conf{SshPath}
If a variable is followed by a "+" it is shell escaped. This is
necessary for the command part of ssh or rsh, since it ends up
getting passed through the shell.
This setting only matters if $Conf{XferMethod} = 'tar'.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{TarFullArgs} = '$fileList+';
Extra tar arguments for full backups. Several variables are
substituted at run-time. See $Conf{TarClientCmd} for the list of
variable substitutions.
If you are running tar locally (ie: without rsh or ssh) then remove
the "+" so that the argument is no longer shell escaped.
This setting only matters if $Conf{XferMethod} = 'tar'.
$Conf{TarIncrArgs} = '--newer=$incrDate+ $fileList+';
Extra tar arguments for incr backups. Several variables are
substituted at run-time. See $Conf{TarClientCmd} for the list of
variable substitutions.
Note that GNU tar has several methods for specifying incremental
backups, including:
--newer-mtime $incrDate+
This causes a file to be included if the modification time is
later than $incrDate (meaning its contents might have changed).
But changes in the ownership or modes will not qualify the
file to be included in an incremental.
--newer=$incrDate+
This causes the file to be included if any attribute of the
file is later than $incrDate, meaning either attributes or
the modification time. This is the default method. Do
not use --atime-preserve in $Conf{TarClientCmd} above,
otherwise resetting the atime (access time) counts as an
attribute change, meaning the file will always be included
in each new incremental dump.
If you are running tar locally (ie: without rsh or ssh) then remove
the "+" so that the argument is no longer shell escaped.
This setting only matters if $Conf{XferMethod} = 'tar'.
$Conf{TarClientRestoreCmd} = '$sshPath -q -x -l root $host' ...
Full command to run tar for restore on the client. GNU tar is
required. This can be the same as $Conf{TarClientCmd}, with tar's
-c replaced by -x and ssh's -n removed.
See $Conf{TarClientCmd} for full details.
This setting only matters if $Conf{XferMethod} = "tar".
If you want to disable direct restores using tar, you should set
$Conf{TarClientRestoreCmd} to undef and the corresponding CGI
restore option will be removed.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{TarClientPath} = '';
Full path for tar on the client. Security caution: normal users
should not allowed to write to this file or directory.
This setting only matters if $Conf{XferMethod} = 'tar'.
$Conf{RsyncClientPath} = '';
Path to rsync executable on the client
$Conf{RsyncClientCmd} = '$sshPath -q -x -l root $host $rsyncPath
$argList+';
Full command to run rsync on the client machine. The following
variables are substituted at run-time:
$host host name being backed up
$hostIP host's IP address
$shareName share name to backup (ie: top-level directory path)
$rsyncPath same as $Conf{RsyncClientPath}
$sshPath same as $Conf{SshPath}
$argList argument list, built from $Conf{RsyncArgs},
$shareName, $Conf{BackupFilesExclude} and
$Conf{BackupFilesOnly}
This setting only matters if $Conf{XferMethod} = 'rsync'.
$Conf{RsyncClientRestoreCmd} = '$sshPath -q -x -l root $host $rsyncPath
$argList+';
Full command to run rsync for restore on the client. The following
variables are substituted at run-time:
$host host name being backed up
$hostIP host's IP address
$shareName share name to backup (ie: top-level directory path)
$rsyncPath same as $Conf{RsyncClientPath}
$sshPath same as $Conf{SshPath}
$argList argument list, built from $Conf{RsyncArgs},
$shareName, $Conf{BackupFilesExclude} and
$Conf{BackupFilesOnly}
This setting only matters if $Conf{XferMethod} = 'rsync'.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{RsyncShareName} = '/';
Share name to backup. For $Conf{XferMethod} = "rsync" this should
be a file system path, eg '/' or '/home'.
For $Conf{XferMethod} = "rsyncd" this should be the name of the
module to backup (ie: the name from /etc/rsynd.conf).
This can also be a list of multiple file system paths or modules.
For example, by adding --one-file-system to $Conf{RsyncArgs} you
can backup each file system separately, which makes restoring one
bad file system easier. In this case you would list all of the
mount points:
$Conf{RsyncShareName} = ['/', '/var', '/data', '/boot'];
$Conf{RsyncdClientPort} = 873;
Rsync daemon port on the client, for $Conf{XferMethod} = "rsyncd".
$Conf{RsyncdUserName} = '';
Rsync daemon user name on client, for $Conf{XferMethod} = "rsyncd".
The user name and password are stored on the client in whatever
file the "secrets file" parameter in rsyncd.conf points to (eg:
/etc/rsyncd.secrets).
$Conf{RsyncdPasswd} = '';
Rsync daemon user name on client, for $Conf{XferMethod} = "rsyncd".
The user name and password are stored on the client in whatever
file the "secrets file" parameter in rsyncd.conf points to (eg:
/etc/rsyncd.secrets).
$Conf{RsyncdAuthRequired} = 1;
Whether authentication is mandatory when connecting to the client's
rsyncd. By default this is on, ensuring that BackupPC will refuse
to connect to an rsyncd on the client that is not password
protected. Turn off at your own risk.
$Conf{RsyncCsumCacheVerifyProb} = 0.01;
When rsync checksum caching is enabled (by adding the
--checksum-seed=32761 option to $Conf{RsyncArgs}), the cached
checksums can be occasionally verified to make sure the file
contents matches the cached checksums. This is to avoid the risk
that disk problems might cause the pool file contents to get
corrupted, but the cached checksums would make BackupPC think that
the file still matches the client.
This setting is the probability (0 means never and 1 means always)
that a file will be rechecked. Setting it to 0 means the checksums
will not be rechecked (unless there is a phase 0 failure). Setting
it to 1 (ie: 100%) means all files will be checked, but that is not
a desirable setting since you are better off simply turning caching
off (ie: remove the --checksum-seed option).
The default of 0.01 means 1% (on average) of the files during a
full backup will have their cached checksum re-checked.
This setting has no effect unless checksum caching is turned on.
$Conf{RsyncArgs} = [ ... ];
Arguments to rsync for backup. Do not edit the first set unless
you have a thorough understanding of how File::RsyncP works.
Examples of additional arguments that should work are
--exclude/--include, eg:
$Conf{RsyncArgs} = [
# original arguments here
'-v',
'--exclude', '/proc',
'--exclude', '*.tmp',
];
$Conf{RsyncRestoreArgs} = [ ... ];
Arguments to rsync for restore. Do not edit the first set unless
you have a thorough understanding of how File::RsyncP works.
If you want to disable direct restores using rsync (eg: is the
module is read-only), you should set $Conf{RsyncRestoreArgs} to
undef and the corresponding CGI restore option will be removed.
$Conf{BackupPCdShareName} = '/';
Share name to backup. For $Conf{XferMethod} = "backuppcd" this
should be a file system path, eg '/' or '/home'.
This can also be a list of multiple file system paths or modules.
(Can it??)
$Conf{BackupPCdShareName} = ['/', '/var', '/data', '/boot'];
$Conf{BackupPCdPath} = '';
Path to backuppcd executable on the server
$Conf{BackupPCdCmd} = '$bpcdPath $host $shareName $poolDir XXXX
$poolCompress $topDir/pc/$client/new';
Full command to run backuppcd on the server to backup a given
client machine. The following variables are substituted at run-
time (TODO: update this list)
$host host name being backed up
$hostIP host's IP address
$shareName share name to backup (ie: top-level directory path)
$backuppcdPath same as $Conf{BackupPCdPath}
$sshPath same as $Conf{SshPath}
This setting only matters if $Conf{XferMethod} = 'backuppcd'.
Arguments to backupcpd are:
- the host name to backup
- the share name to backup
- the directory where the pool is
- the directory where the last run was (NOT DONE YET)
- a boolean value indicating whether or not the pool is
compressed or not
- the directory where the new run should occur (currently it assumes ".")
$Conf{BackupPCdRestoreCmd} = '$bpcdPath TODO';
Full command to run backuppcd on the server for restore to a client
machine. The following variables are substituted at run-time
(TODO: update this list)
$host host name being backed up
$hostIP host's IP address
$shareName share name to backup (ie: top-level directory path)
$backuppcdPath same as $Conf{BackupPCdPath}
$sshPath same as $Conf{SshPath}
This setting only matters if $Conf{XferMethod} = 'backuppcd'.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{ArchiveDest} = '/tmp';
Archive Destination
The Destination of the archive e.g. /tmp for file archive or
/dev/nst0 for device archive
$Conf{ArchiveComp} = 'gzip';
Archive Compression type
The valid values are:
- 'none': No Compression
- 'gzip': Medium Compression. Recommended.
- 'bzip2': High Compression but takes longer.
$Conf{ArchivePar} = 0;
Archive Parity Files
The amount of Parity data to generate, as a percentage of the
archive size. Uses the commandline par2 (par2cmdline) available
from http://parchive.sourceforge.net
Only useful for file dumps.
Set to 0 to disable this feature.
$Conf{ArchiveSplit} = 0;
Archive Size Split
Only for file archives. Splits the output into the specified size *
1,000,000. e.g. to split into 650,000,000 bytes, specify 650
below.
If the value is 0, or if $Conf{ArchiveDest} is an existing file or
device (e.g. a streaming tape drive), this feature is disabled.
$Conf{ArchiveClientCmd} = '$Installdir/bin/BackupPC_archiveHost' ...
Archive Command
This is the command that is called to actually run the archive
process for each host. The following variables are substituted at
run-time:
$Installdir The installation directory of BackupPC
$tarCreatePath The path to BackupPC_tarCreate
$splitpath The path to the split program
$parpath The path to the par2 program
$host The host to archive
$backupnumber The backup number of the host to archive
$compression The path to the compression program
$compext The extension assigned to the compression type
$splitsize The number of bytes to split archives into
$archiveloc The location to put the archive
$parfile The amount of parity data to create (percentage)
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{SshPath} = '';
Full path for ssh. Security caution: normal users should not
allowed to write to this file or directory.
$Conf{NmbLookupPath} = '';
Full path for nmblookup. Security caution: normal users should not
allowed to write to this file or directory.
nmblookup is from the Samba distribution. nmblookup is used to get
the netbios name, necessary for DHCP hosts.
$Conf{NmbLookupCmd} = '$nmbLookupPath -A $host';
NmbLookup command. Given an IP address, does an nmblookup on that
IP address. The following variables are substituted at run-time:
$nmbLookupPath path to nmblookup ($Conf{NmbLookupPath})
$host IP address
This command is only used for DHCP hosts: given an IP address, this
command should try to find its NetBios name.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{NmbLookupFindHostCmd} = '$nmbLookupPath $host';
NmbLookup command. Given a netbios name, finds that host by doing
a NetBios lookup. Several variables are substituted at run-time:
$nmbLookupPath path to nmblookup ($Conf{NmbLookupPath})
$host NetBios name
In some cases you might need to change the broadcast address, for
example if nmblookup uses 192.168.255.255 by default and you find
that doesn't work, try 192.168.1.255 (or your equivalent class C
address) using the -B option:
$Conf{NmbLookupFindHostCmd} = '$nmbLookupPath -B 192.168.1.255 $host';
If you use a WINS server and your machines don't respond to
multicast NetBios requests you can use this (replace 1.2.3.4 with
the IP address of your WINS server):
$Conf{NmbLookupFindHostCmd} = '$nmbLookupPath -R -U 1.2.3.4 $host';
This is preferred over multicast since it minimizes network
traffic.
Experiment manually for your site to see what form of nmblookup
command works.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{FixedIPNetBiosNameCheck} = 0;
For fixed IP address hosts, BackupPC_dump can also verify the
netbios name to ensure it matches the host name. An error is
generated if they do not match. Typically this flag is off. But
if you are going to transition a bunch of machines from fixed host
addresses to DHCP, setting this flag is a great way to verify that
the machines have their netbios name set correctly before turning
on DCHP.
$Conf{PingPath} = '';
Full path to the ping command. Security caution: normal users
should not be allowed to write to this file or directory.
If you want to disable ping checking, set this to some program that
exits with 0 status, eg:
$Conf{PingPath} = '/bin/echo';
$Conf{PingCmd} = '$pingPath -c 1 $host';
Ping command. The following variables are substituted at run-time:
$pingPath path to ping ($Conf{PingPath})
$host host name
Wade Brown reports that on solaris 2.6 and 2.7 ping -s returns the
wrong exit status (0 even on failure). Replace with "ping $host
1", which gets the correct exit status but we don't get the round-
trip time.
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{PingMaxMsec} = 20;
Maximum round-trip ping time in milliseconds. This threshold is
set to avoid backing up PCs that are remotely connected through WAN
or dialup connections. The output from ping -s (assuming it is
supported on your system) is used to check the round-trip packet
time. On your local LAN round-trip times should be much less than
20msec. On most WAN or dialup connections the round-trip time will
be typically more than 20msec. Tune if necessary.
$Conf{CompressLevel} = 0;
Compression level to use on files. 0 means no compression.
Compression levels can be from 1 (least cpu time, slightly worse
compression) to 9 (most cpu time, slightly better compression).
The recommended value is 3. Changing to 5, for example, will take
maybe 20% more cpu time and will get another 2-3% additional
compression. See the zlib documentation for more information about
compression levels.
Changing compression on or off after backups have already been done
will require both compressed and uncompressed pool files to be
stored. This will increase the pool storage requirements, at least
until all the old backups expire and are deleted.
It is ok to change the compression value (from one non-zero value
to another non-zero value) after dumps are already done. Since
BackupPC matches pool files by comparing the uncompressed versions,
it will still correctly match new incoming files against existing
pool files. The new compression level will take effect only for
new files that are newly compressed and added to the pool.
If compression was off and you are enabling compression for the
first time you can use the BackupPC_compressPool utility to
compress the pool. This avoids having the pool grow to accommodate
both compressed and uncompressed backups. See the documentation
for more information.
Note: compression needs the Compress::Zlib perl library. If the
Compress::Zlib library can't be found then $Conf{CompressLevel} is
forced to 0 (compression off).
$Conf{ClientTimeout} = 72000;
Timeout in seconds when listening for the transport program's
(smbclient, tar etc) stdout. If no output is received during this
time, then it is assumed that something has wedged during a backup,
and the backup is terminated.
Note that stdout buffering combined with huge files being backed up
could cause longish delays in the output from smbclient that
BackupPC_dump sees, so in rare cases you might want to increase
this value.
Despite the name, this parameter sets the timeout for all transport
methods (tar, smb etc).
$Conf{MaxOldPerPCLogFiles} = 12;
Maximum number of log files we keep around in each PC's directory
(ie: pc/$host). These files are aged monthly. A setting of 12
means there will be at most the files LOG, LOG.0, LOG.1, ... LOG.11
in the pc/$host directory (ie: about a years worth). (Except this
month's LOG, these files will have a .z extension if compression is
on).
If you decrease this number after BackupPC has been running for a
while you will have to manually remove the older log files.
$Conf{DumpPreUserCmd} = undef;
$Conf{DumpPostUserCmd} = undef;
$Conf{DumpPreShareCmd} = undef;
$Conf{DumpPostShareCmd} = undef;
$Conf{RestorePreUserCmd} = undef;
$Conf{RestorePostUserCmd} = undef;
$Conf{ArchivePreUserCmd} = undef;
$Conf{ArchivePostUserCmd} = undef;
Optional commands to run before and after dumps and restores, and
also before and after each share of a dump.
Stdout from these commands will be written to the Xfer (or Restore)
log file. One example of using these commands would be to shut
down and restart a database server, dump a database to files for
backup, or doing a snapshot of a share prior to a backup. Example:
$Conf{DumpPreUserCmd} = '$sshPath -q -x -l root $host /usr/bin/dumpMysql';
The following variable substitutions are made at run time for
$Conf{DumpPreUserCmd}, $Conf{DumpPostUserCmd},
$Conf{DumpPreShareCmd} and $Conf{DumpPostShareCmd}:
$type type of dump (incr or full)
$xferOK 1 if the dump succeeded, 0 if it didn't
$client client name being backed up
$host host name (could be different from client name if
$Conf{ClientNameAlias} is set)
$hostIP IP address of host
$user user name from the hosts file
$moreUsers list of additional users from the hosts file
$share the first share name (or current share for
$Conf{DumpPreShareCmd} and $Conf{DumpPostShareCmd})
$shares list of all the share names
$XferMethod value of $Conf{XferMethod} (eg: tar, rsync, smb)
$sshPath value of $Conf{SshPath},
$cmdType set to DumpPreUserCmd or DumpPostUserCmd
The following variable substitutions are made at run time for
$Conf{RestorePreUserCmd} and $Conf{RestorePostUserCmd}:
$client client name being backed up
$xferOK 1 if the restore succeeded, 0 if it didn't
$host host name (could be different from client name if
$Conf{ClientNameAlias} is set)
$hostIP IP address of host
$user user name from the hosts file
$moreUsers list of additional users from the hosts file
$share the first share name
$XferMethod value of $Conf{XferMethod} (eg: tar, rsync, smb)
$sshPath value of $Conf{SshPath},
$type set to "restore"
$bkupSrcHost host name of the restore source
$bkupSrcShare share name of the restore source
$bkupSrcNum backup number of the restore source
$pathHdrSrc common starting path of restore source
$pathHdrDest common starting path of destination
$fileList list of files being restored
$cmdType set to RestorePreUserCmd or RestorePostUserCmd
The following variable substitutions are made at run time for
$Conf{ArchivePreUserCmd} and $Conf{ArchivePostUserCmd}:
$client client name being backed up
$xferOK 1 if the archive succeeded, 0 if it didn't
$host Name of the archive host
$user user name from the hosts file
$share the first share name
$XferMethod value of $Conf{XferMethod} (eg: tar, rsync, smb)
$HostList list of hosts being archived
$BackupList list of backup numbers for the hosts being archived
$archiveloc location where the archive is sent to
$parfile amount of parity data being generated (percentage)
$compression compression program being used (eg: cat, gzip, bzip2)
$compext extension used for compression type (eg: raw, gz, bz2)
$splitsize size of the files that the archive creates
$sshPath value of $Conf{SshPath},
$type set to "archive"
$cmdType set to ArchivePreUserCmd or ArchivePostUserCmd
Note: all Cmds are executed directly without a shell, so the prog
name needs to be a full path and you can't include shell syntax
like redirection and pipes; put that in a script if you need it.
$Conf{UserCmdCheckStatus} = 0;
Whether the exit status of each PreUserCmd and PostUserCmd is
checked.
If set and the Dump/Restore/Archive Pre/Post UserCmd returns a non-
zero exit status then the dump/restore/archive is aborted. To
maintain backward compatibility (where the exit status in early
versions was always ignored), this flag defaults to 0.
If this flag is set and the Dump/Restore/Archive PreUserCmd fails
then the matching Dump/Restore/Archive PostUserCmd is not executed.
If DumpPreShareCmd returns a non-exit status, then DumpPostShareCmd
is not executed, but the DumpPostUserCmd is still run (since
DumpPreUserCmd must have previously succeeded).
An example of a DumpPreUserCmd that might fail is a script that
snapshots or dumps a database which fails because of some database
error.
$Conf{ClientNameAlias} = undef;
Override the client's host name. This allows multiple clients to
all refer to the same physical host. This should only be set in
the per-PC config file and is only used by BackupPC at the last
moment prior to generating the command used to backup that machine
(ie: the value of $Conf{ClientNameAlias} is invisible everywhere
else in BackupPC). The setting can be a host name or IP address,
eg:
$Conf{ClientNameAlias} = 'realHostName';
$Conf{ClientNameAlias} = '192.1.1.15';
will cause the relevant smb/tar/rsync backup/restore commands to be
directed to realHostName, not the client name.
Note: this setting doesn't work for hosts with DHCP set to 1.
Email reminders, status and messages
$Conf{SendmailPath} = '';
Full path to the sendmail command. Security caution: normal users
should not allowed to write to this file or directory.
$Conf{EMailNotifyMinDays} = 2.5;
Minimum period between consecutive emails to a single user. This
tries to keep annoying email to users to a reasonable level. Email
checks are done nightly, so this number is effectively rounded up
(ie: 2.5 means a user will never receive email more than once every
3 days).
$Conf{EMailFromUserName} = '';
Name to use as the "from" name for email. Depending upon your mail
handler this is either a plain name (eg: "admin") or a fully-
qualified name (eg: "admin@mydomain.com").
$Conf{EMailAdminUserName} = '';
Destination address to an administrative user who will receive a
nightly email with warnings and errors. If there are no warnings
or errors then no email will be sent. Depending upon your mail
handler this is either a plain name (eg: "admin") or a fully-
qualified name (eg: "admin@mydomain.com").
$Conf{EMailUserDestDomain} = '';
Destination domain name for email sent to users. By default this
is empty, meaning email is sent to plain, unqualified addresses.
Otherwise, set it to the destintation domain, eg:
$Cong{EMailUserDestDomain} = '@mydomain.com';
With this setting user email will be set to 'user@mydomain.com'.
$Conf{EMailNoBackupEverSubj} = undef;
$Conf{EMailNoBackupEverMesg} = undef;
This subject and message is sent to a user if their PC has never
been backed up.
These values are language-dependent. The default versions can be
found in the language file (eg: lib/BackupPC/Lang/en.pm). If you
need to change the message, copy it here and edit it, eg:
$Conf{EMailNoBackupEverMesg} = <<'EOF';
To: $user$domain
cc:
Subject: $subj
Dear $userName,
This is a site-specific email message.
EOF
$Conf{EMailNotifyOldBackupDays} = 7.0;
How old the most recent backup has to be before notifying user.
When there have been no backups in this number of days the user is
sent an email.
$Conf{EMailNoBackupRecentSubj} = undef;
$Conf{EMailNoBackupRecentMesg} = undef;
This subject and message is sent to a user if their PC has not
recently been backed up (ie: more than
$Conf{EMailNotifyOldBackupDays} days ago).
These values are language-dependent. The default versions can be
found in the language file (eg: lib/BackupPC/Lang/en.pm). If you
need to change the message, copy it here and edit it, eg:
$Conf{EMailNoBackupRecentMesg} = <<'EOF';
To: $user$domain
cc:
Subject: $subj
Dear $userName,
This is a site-specific email message.
EOF
$Conf{EMailNotifyOldOutlookDays} = 5.0;
How old the most recent backup of Outlook files has to be before
notifying user.
$Conf{EMailOutlookBackupSubj} = undef;
$Conf{EMailOutlookBackupMesg} = undef;
This subject and message is sent to a user if their Outlook files
have not recently been backed up (ie: more than
$Conf{EMailNotifyOldOutlookDays} days ago).
These values are language-dependent. The default versions can be
found in the language file (eg: lib/BackupPC/Lang/en.pm). If you
need to change the message, copy it here and edit it, eg:
$Conf{EMailOutlookBackupMesg} = <<'EOF';
To: $user$domain
cc:
Subject: $subj
Dear $userName,
This is a site-specific email message.
EOF
$Conf{EMailHeaders} = <<EOF;
Additional email headers. If you change the charset to utf8 then
BackupPC_sendEmail will use utf8 for the email body.
CGI user interface configuration settings
$Conf{CgiAdminUserGroup} = '';
$Conf{CgiAdminUsers} = '';
Normal users can only access information specific to their host.
They can start/stop/browse/restore backups.
Administrative users have full access to all hosts, plus overall
status and log information.
The administrative users are the union of the unix/linux group
$Conf{CgiAdminUserGroup} and the manual list of users, separated by
spaces, in $Conf{CgiAdminUsers}. If you don't want a group or
manual list of users set the corresponding configuration setting to
undef or an empty string.
If you want every user to have admin privileges (careful!), set
$Conf{CgiAdminUsers} = '*'.
Examples:
$Conf{CgiAdminUserGroup} = 'admin';
$Conf{CgiAdminUsers} = 'craig celia';
--> administrative users are the union of group admin, plus
craig and celia.
$Conf{CgiAdminUserGroup} = '';
$Conf{CgiAdminUsers} = 'craig celia';
--> administrative users are only craig and celia'.
$Conf{CgiURL} = undef;
URL of the BackupPC_Admin CGI script. Used for email messages.
$Conf{Language} = 'en';
Language to use. See lib/BackupPC/Lang for the list of supported
languages, which include English (en), French (fr), Spanish (es),
German (de), Italian (it), Dutch (nl), Polish (pl), Portuguese
Brazillian (pt_br) and Chinese (zh_CH).
Currently the Language setting applies to the CGI interface and
email messages sent to users. Log files and other text are still
in English.
$Conf{CgiUserHomePageCheck} = '';
$Conf{CgiUserUrlCreate} = 'mailto:%s';
User names that are rendered by the CGI interface can be turned
into links into their home page or other information about the
user. To set this up you need to create two sprintf() strings,
that each contain a single '%s' that will be replaced by the user
name. The default is a mailto: link.
$Conf{CgiUserHomePageCheck} should be an absolute file path that is
used to check (via "-f") that the user has a valid home page. Set
this to undef or an empty string to turn off this check.
$Conf{CgiUserUrlCreate} should be a full URL that points to the
user's home page. Set this to undef or an empty string to turn off
generation of URLs for user names.
Example:
$Conf{CgiUserHomePageCheck} = '/var/www/html/users/%s.html';
$Conf{CgiUserUrlCreate} = 'http://myhost/users/%s.html';
--> if /var/www/html/users/craig.html exists, then 'craig' will
be rendered as a link to http://myhost/users/craig.html.
$Conf{CgiDateFormatMMDD} = 1;
Date display format for CGI interface. A value of 1 uses US-style
dates (MM/DD), a value of 2 uses full YYYY-MM-DD format, and zero
for international dates (DD/MM).
$Conf{CgiNavBarAdminAllHosts} = 1;
If set, the complete list of hosts appears in the left navigation
bar pull-down for administrators. Otherwise, just the hosts for
which the user is listed in the host file (as either the user or in
moreUsers) are displayed.
$Conf{CgiSearchBoxEnable} = 1;
Enable/disable the search box in the navigation bar.
$Conf{CgiNavBarLinks} = [ ... ];
Additional navigation bar links. These appear for both regular
users and administrators. This is a list of hashes giving the link
(URL) and the text (name) for the link. Specifying lname instead
of name uses the language specific string (ie: $Lang->{lname})
instead of just literally displaying name.
$Conf{CgiStatusHilightColor} = { ...
Hilight colors based on status that are used in the PC summary
page.
$Conf{CgiHeaders} = '<meta http-equiv="pragma" content="no-cache">';
Additional CGI header text.
$Conf{CgiImageDir} = '';
Directory where images are stored. This directory should be below
Apache's DocumentRoot. This value isn't used by BackupPC but is
used by configure.pl when you upgrade BackupPC.
Example:
$Conf{CgiImageDir} = '/usr/local/apache/htdocs/BackupPC';
$Conf{CgiExt2ContentType} = { };
Additional mappings of file name extenions to Content-Type for
individual file restore. See $Ext2ContentType in BackupPC_Admin
for the default setting. You can add additional settings here, or
override any default settings. Example:
$Conf{CgiExt2ContentType} = {
'pl' => 'text/plain',
};
$Conf{CgiImageDirURL} = '';
URL (without the leading http://host) for BackupPC's image
directory. The CGI script uses this value to serve up image files.
Example:
$Conf{CgiImageDirURL} = '/BackupPC';
$Conf{CgiCSSFile} = 'BackupPC_stnd.css';
CSS stylesheet "skin" for the CGI interface. It is stored in the
$Conf{CgiImageDir} directory and accessed via the
$Conf{CgiImageDirURL} URL.
For BackupPC v3.x several color, layout and font changes were made.
The previous v2.x version is available as BackupPC_stnd_orig.css,
so if you prefer the old skin, change this to
BackupPC_stnd_orig.css.
$Conf{CgiUserConfigEditEnable} = 1;
Whether the user is allowed to edit their per-PC config.
$Conf{CgiUserConfigEdit} = { ...
Which per-host config variables a non-admin user is allowed to
edit. Admin users can edit all per-host config variables, even if
disabled in this list.
SECURITY WARNING: Do not let users edit any of the Cmd config
variables! That's because a user could set a Cmd to a shell script
of their choice and it will be run as the BackupPC user. That
script could do all sorts of bad things.
Version Numbers
Starting with v1.4.0 BackupPC uses a X.Y.Z version numbering system,
instead of X.0Y. The first digit is for major new releases, the middle
digit is for significant feature releases and improvements (most of the
releases have been in this category), and the last digit is for bug
fixes. You should think of the old 1.00, 1.01, 1.02 and 1.03 as 1.0.0,
1.1.0, 1.2.0 and 1.3.0.
Additionally, patches might be made available. A patched version
number is of the form X.Y.ZplN (eg: 2.1.0pl2), where N is the patch
level.
Author
Craig Barratt <cbarratt@users.sourceforge.net>
See <http://backuppc.sourceforge.net>.
Copyright
Copyright (C) 2001-2007 Craig Barratt
Credits
Ryan Kucera contributed the directory navigation code and images for
v1.5.0. He contributed the first skeleton of BackupPC_restore. He
also added a significant revision to the CGI interface, including CSS
tags, in v2.1.0, and designed the BackupPC logo.
Xavier Nicollet, with additions from Guillaume Filion, added the
internationalization (i18n) support to the CGI interface for v2.0.0.
Xavier provided the French translation fr.pm, with additions from
Guillaume.
Guillaume Filion wrote BackupPC_zipCreate and added the CGI support for
zip download, in addition to some CGI cleanup, for v1.5.0. Guillaume
continues to support fr.pm updates for each new version.
Josh Marshall implemented the Archive feature in v2.1.0.
Ludovic Drolez supports the BackupPC Debian package.
Javier Gonzalez provided the Spanish translation, es.pm for v2.0.0.
Manfred Herrmann provided the German translation, de.pm for v2.0.0.
Manfred continues to support de.pm updates for each new version,
together with some help from Ralph Passgang.
Lorenzo Cappelletti provided the Italian translation, it.pm for v2.1.0.
Giuseppe Iuculano and Vittorio Macchi updated it for 3.0.0.
Lieven Bridts provided the Dutch translation, nl.pm, for v2.1.0, with
some tweaks from Guus Houtzager, and updates for 3.0.0.
Reginaldo Ferreira provided the Portuguese Brazillian translation
pt_br.pm for v2.2.0.
Rich Duzenbury provided the RSS feed option to the CGI interface.
Jono Woodhouse from CapeSoft Software (www.capesoft.com) provided a new
CSS skin for 3.0.0 with several layout improvements. Sean Cameron
(also from CapeSoft) designed new and more compact file icons for
3.0.0.
Youlin Feng provided the Chinese translation for 3.1.0.
Karol 'Semper' Stelmaczonek provided the Polish translation for 3.1.0.
Jeremy Tietsort provided the host summary table sorting feature for
3.1.0.
Many people have reported bugs, made useful suggestions and helped with
testing; see the ChangeLog and the mailing lists.
Your name could appear here in the next version!
License
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License in
the LICENSE file along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.