NAME
faubackup - Backup System using a Filesystem for Storage
SYNOPSIS
faubackup-gather [-v|--verbose] [--atime-preserve
faubackup-scatter [-v|--verbose]
DESCRIPTION
faubackup-gather, faubackup-scatter uses a filesystem on a hard drive
for incremental and full backups. This enables the backup to be
accessable through standard filesystem tools.
Later Backups to the same filesystem will automatically be incremental,
as unchanged files are only hard-linked with the existing version of
the file.
faubackup-gather reads a NUL-delimited list of filenames from stdin and
serializes the contents of these files to stdout in a special format,
containing all inode informations. All Error messages or other output
are written to stderr. To backup the current directory you can use
’faubackup-find | faubackup-gather’. To be able to correctly read all
files, faubackup-gather should be run as the superuser.
faubackup-scatter will read contents of directories from stdin, and
recreate all files. stdin must be in the format used by
faubackup-gather. It first creates a directory for current date and
time inside the current directory (e.g. ’./2001-02-07@03:20:10’).
Everything written will go into this directory or subdirectories.
Everything read by faubackup-gather will be recreated with exactly the
same names, contents, permissions and times (with one exeption: inode
change time will be the time of the backup). Thus, these two programs
are capable of backing up directories just like cpio and tar.
faubackup-scatter can deal with holes in files. To be able to
correctly set all permissions, faubackup-scatter should be run as the
superuser.
faubackup-scatter will detect if there are other backups to the same
destination directory (with only differing timestamps). In this case,
files that haven’t changed since the last backups will not be written
to the filesystem, but instead hard-linked against the previous
version. Thus, diskspace is only needed for the directory inodes and
for changed files.
To be able to hard-link files, faubackup-scatter will create an
additional directory, ..inodes, which contains all files, named after
their inode (this is: device/inode of the source). These entries are
hardlinked to the actual location where they are stored in the backup.
To be able to detect a broken transmission, a special entry (".") is
used as an end-of-backup marker. If the connection between the gather
and scatter programs suddenly breaks (e.g. because of network outage),
faubackup-scatter will detect the missing end-of-backup marker and will
mark the backup as broken. To make that system work, the filelist feed
into faubackup-gather has to end with a single dot. But that is a good
idea anyway, as it ensures that access rights for the root directory of
the backup are set correctly. "faubackup-find already generates this
marker automatically.
If you want to remove an old backup, simply delete the directory
created by faubackup-scatter (the one named after the backup-time).
When the same version of a file is needed by an other backup, it will
still remain on the disk.
OPTIONS
-v --verbose
Show verbose output. This includes all filenames being
read/written.
--atime-preserve
Try to reset the access time to its previous value after reading
a file which is to be backed up. Doing so will update the
ctime, too. Don’t use this option if you are using other backup
software in parallel, because it might think that all your files
have changed.
FORMAT
The format used by these tools includes the filenames, device numbers,
inode-numbers, inode-contents and file contents of all inodes in a
binary format.
The exact format is subject to change. Look at the source for details.
BUGS
Please report all bugs to faubackup-user@lists.sourceforge.net.
SEE ALSO
faubackup(8), faubackup-find(8), cpio(1), tar(1), find(1), ls(1),
grep(1).
COPYRIGHT
FauBackup is Copyright (c) 2000-01 Dr. Volkmar Sieh, (c) 2000-06 Martin
Waitz. Developed at Friedrich-Alexander-University Erlangen-Nuremberg.
FauBackup comes with ABSOLUTELY NO WARRANTY. This 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, or (at your option) any later version. Look at
COPYING for details.
AUTHOR
This manual page was written by Martin Waitz <tali@admingilde.org>
CONTACT
mailto:faubackup-user@lists.sourceforge.net
June 23, 2003 FAUBACKUP(8)