NAME
hdup - harddisk duplicator/harddisk backupper - backup to harddisk
SYNOPSIS
hdup [ OPTION ] SCHEME HOST [ @USER@REMOTEHOST ] (1st format)
hdup [ OPTION ] restore HOST DATE DIRECTORY [ @USER@REMOTEHOST ] (2nd
format)
DESCRIPTION
Hdup is used to backup a filesystem. Features include:
o incremental backups: monthly, weekly and daily dumps,
o encryption of the archive (via mcrypt or GPG),
o compression of the archive (bzip/gzip/lzop/none),
o possibility to transfer the archive to a remote host,
o possibility to restore the archive from a remote host,
o ability to split up archives,
o no obscure archive format (it is a normal compressed tar file),
and
o simple to use.
The behaviour of hdup is controlled by its configuration file (see
hdup.conf(5)). Internally hdup uses GNU tar to actually create the
backups.
First format
When using the 1st format hdup performs a backup. Remember: hdup pushes
a backup from the localhost to the remote host.
The sort of backup is specified by SCHEME:
monthly
Make a full (null) dump of the filesystem.
weekly Make an incremental dump of the filesystem relative to the
latest monthly dump. If hdup cannot find a monthly dump it will
complain, unless always backup is on. Then a monthly dump will
be performed.
daily Make an incremental dump of the filesystem relative to the
latest weekly dump. If hdup cannot find a weekly dump it will
complain, unless always backup is on. Then a weekly dump will be
performed.
HOST is the host of which hdup should perform the backup. This should
match a ’[HOST]’ statement in the configuration file. The directories
of that host (specified with ’dir = dir1, dir2’, ...) will be backed up
to the directory specified with ’archive dir = dir’. If HOST is not
found no backup will be made.
@USER@REMOTEHOST is the host to which the archive should be transfered.
This must include the user name. E.g @miekg@elektron.atoom.net. It is
illegal to specify the colon :. hdup must be present on the remote
host. The location of this remote hdup is specified using remote hdup.
Any program capable of transferring files can used for this purpose.
Currently tested is ssh. Other programs like rsync (not tested) may
also work. Any program with the following characteristics will do:
o must be usable as a filter (read from stdin, write to stdout),
o must support user@remotehost syntax.
Second format
When using the 2nd format a previous backed up filesystem is restored.
Remember: hdup pushes a restore from the remote to the local host. This
is opposite from the backup operation!
HOST is the host who’s archives should be restored.
DATE everything up to this date will be restored. hdup will look for
the most recent monthly archive, then the most recent weekly and
finally for the daily to pad up to date given. The DATE can either be
specified as DD-MM-YYYY (date spec = default), as YYYY-MM-DD (date spec
= iso) or as MM-DD-YYYY (date spec = american). This is controlled from
the configuration file.
A special date is ’static’ which instructs hdup to look in the ’static’
directory. This is used when ’no history = yes’. This is dangerous to
use because hdup will overwrite the old backup file with the new one.
When your system crashes during the overwrite you have no backup at
all! Only use this when you really don’t have room for two monthly
backups.
Another special date is ’today’ which instructs hdup to use the current
date.
DIRECTORY tells hdup to which directory the archive should be untarred
to. Be very careful when running hdup as root and specifying ’/’ as the
directory. Version 1.4 and above refuses to restore to ’/’. This can
be overridden by specifying ’force = on/yes’ in the configuration.
@USER@REMOTEHOST is the host to which the archive should be restored.
This must include the user name. E.g @miekg@elektron.atoom.net. As as
version 1.6.6 it is illegal to specify the colon :. On the remosthost
and in DIRECTORY the archive is restored. hdup must be present on the
remote host.
Status message
When hdup is finished with its current operation it will print an
overview message:
Hdup version.: 1.6.6
Host.........: elektron
Date.........: 2003-02-02
Scheme.......: monthly
Archive......: elektron.2003-02-02.monthly.tar.gz
Encryption...: no
Archive size.: 257k
Elapsed......: 0:01:27
Status.......: successfully performed backup
Which can be mailed to you via cron.
OPTIONS
-c, --config=config
Location of the configuration file. The default location of
hdup’s configuration file is /etc/hdup/hdup.conf.
-s, --specific=file
Restore a specific file from an archive. file must be the full
path to the file, relative paths will not work.
-i, --ignore-tar
Ignore tar errors when restoring.
-I, --ignore-conf
Ignore errors in the configuration file.
-P, --patched_tar
Tar is patched so that it can handle --no-recursion, --listed-
incremental and --files-from together. This options enables two
things in hdup; 1) directory info is written to ’filelist’ and
2) --no-recursion is given to tar.
This solves the bug whereby hdup wouldn’t include directory
information in the archives.
-d, --dryrun
Do a dryrun - don’t do anything with the filesystem
-q, --quiet
Suppress the output of the subprocesses (like ’tar’ and ’ssh’).
-q -q, --quiet --quiet
Suppress the logging output from hdup.
-q -q -q, --quiet --quiet --quiet
No logging at all. Even no overview message.
-V Be more verbose.
-V -V Be even more verbose. This will show which files are backed up
by hdup IF you also supply the -D option.
-h, --help
A help message.
-v, --version
Show the version of hdup.
-D, --debug
Show a lot of information which can aid debugging.
The -V and -q options do not effect each other. A ’-qqq -VV’ option
list will mean that hdup will show what is run, but nothing else (no
overview message and no warning nor errors).
ENCRYPTION
hdup can encrypt the archives, mcrypt is used for the actual
encryption. As of version 1.6.25 GPG can also be used to encrypt the
archive. Note that currently remotely restoring a GPG encrypted
archives is not working.
mcrypt
With mcrypt --list you get a list of the algorithms mcrypt supports:
...
serpent (32): cbc cfb ctr ecb ncfb ofb nofb
wake (32): stream
loki97 (32): cbc cfb ctr ecb ncfb ofb nofb
rijndael-128 (32): cbc cfb ctr ecb ncfb ofb nofb
rijndael-192 (32): cbc cfb ctr ecb ncfb ofb nofb
...
If you want to use loki97 you specify algorithm = loki97 in hdup.conf.
The same goes for all the other algorithms.
GPG
To use GPG the following is needed. Set algorithm = gpg and key = user
ID of key. In my case I’ve created a GPG key with user ID of ’miekg’ so
I use:
algorithm = gpg
key = miekg
The key is supplied to gpg with the -r argument. See the manpage of gpg
for more details.
When restoring a GPG encrypted archive you will be prompted to unlock
your private key.
AUTHOR
Written by Miek Gieben. Wouter van Gils helped a lot with testing pre-
release versions. User feedback is appreciated.
REPORTING BUGS
Report bugs to <hdup-user@miek.nl>.
BUGS
The %a expansion is not always the same in the prerun and postrun
scripts (when using encryption).
LIMITATIONS
Under Linux kernel version 2.2 the archive size cannot exceed two (2)
Gigabyte. If you need larger archives sizes you should upgrade your
kernel. You can however solve this by using chunk size. Just define
your maximum allowed size, something like chunk size = 1800M and you’re
set.
If you encrypt archives and want to restore them, you are forced to use
one encryption scheme for all the backups. hdup does not store the key
and algorithm with the archive, thus it is impossible to restore
archives that use different keys and algorithms.
COPYRIGHT
Copyright (C) 2001-2005 Miek Gieben. This is free software. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE.
SEE ALSO
hdup.conf(5) for information about hdup’s configuration file.
18 Mar 2003 hdup(1)