User Manuals RDIF-BACKUP(1)
NAME
rdiff-backup - local/remote mirror and incremental backup
SYNOPSIS
rdiff-backup [options] [user@]host1.foo]::sourcedirectory
[user@]host2.foo]::destinationdirectory
rdiff-backup {{ -l --list-increments } --remove-older-
than timeinterval --list-at-time time --list-changed-
since time --list-increment-sizes --verify --verify-
at-time time} [user@]host2.foo]::destinationdirectory
rdiff-backup --calculate-average statfile1 statfile2 ...
rdiff-backup --test-server [user1]@host1.net1::path
[user2]@host2.net2::path ...
DESCRIPTION
rdiff-backup is a script, written in python(1) that backs up
one directory to another. The target directory ends up a
copy (mirror) of the source directory, but extra reverse
diffs are stored in a special subdirectory of that target
directory, so you can still recover files lost some time
ago. The idea is to combine the best features of a mirror
and an incremental backup. rdiff-backup also preserves sym-
links, special files, hardlinks, permissions, uid/gid owner-
ship, and modification times.
rdiff-backup can also operate in a bandwidth efficient
manner over a pipe, like rsync(1). Thus you can use ssh and
rdiff-backup to securely back a hard drive up to a remote
location, and only the differences will be transmitted.
Using the default settings, rdiff-backup requires that the
remote system accept ssh connections, and that rdiff-backup
is installed in the user's PATH on the remote system. For
information on other options, see the section on REMOTE
OPERATION.
Note that you should not write to the mirror except with
rdiff-backup. Many of the increments are stored as reverse
diffs, so if you delete or modify a file, you may lose the
ability to restore previous versions of that file.
Finally, this man page is intended more as a precise
description of the behavior and syntax of rdiff-backup. New
users may want to check out the examples.html file included
in the rdiff-backup distribution.
OPTIONS
-b, --backup-mode
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Force backup mode even if first argument appears to be
an increment or mirror file.
--calculate-average
Enter calculate average mode. The arguments should be
a number of statistics files. rdiff-backup will print
the average of the listed statistics files and exit.
--carbonfile
Enable backup of MacOS X carbonfile information.
--check-destination-dir
If an rdiff-backup session fails, running rdiff-backup
with this option on the destination dir will undo the
failed directory. This happens automatically if you
attempt to back up to a directory and the last backup
failed.
--compare
This is equivalent to '--compare-at-time now'
--compare-at-time time
Compare a directory with the backup set at the given
time. This can be useful to see how archived data
differs from current data, or to check that a backup is
current. This only compares metadata, in the same way
rdiff-backup decides whether a file has changed.
--compare-full
This is equivalent to '--compare-full-at-time now'
--compare-full-at-time time
Compare a directory with the backup set at the given
time. To compare regular files, the repository data
will be copied in its entirety to the source side and
compared byte by byte. This is the slowest but most
complete compare option.
--compare-hash
This is equivalent to '--compare-hash-at-time now'
--compare-hash-at-time time
Compare a directory with the backup set at the given
time. Regular files will be compared by computing
their SHA1 digest on the source side and comparing it
to the digest recorded in the metadata.
--create-full-path
Normally only the final directory of the destination
path will be created if it does not exist. With this
option, all missing directories on the destination path
will be created. Use this option with care: if there is
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a typo in the remote path, the remote filesystem could
fill up very quickly (by creating a duplicate backup
tree). For this reason this option is primarily aimed
at scripts which automate backups.
--current-time seconds
This option is useful mainly for testing. If set,
rdiff-backup will use it for the current time instead
of consulting the clock. The argument is the number of
seconds since the epoch.
--exclude shellpattern
Exclude the file or files matched by shellpattern. If
a directory is matched, then files under that directory
will also be matched. See the FILE SELECTION section
for more information.
--exclude-device-files
Exclude all device files. This can be useful for
security/permissions reasons or if rdiff-backup is not
handling device files correctly.
--exclude-fifos
Exclude all fifo files.
--exclude-filelist filename
Excludes the files listed in filename. If filename is
handwritten you probably want --exclude-globbing-
filelist instead. See the FILE SELECTION section for
more information.
--exclude-filelist-stdin
Like --exclude-filelist, but the list of files will be
read from standard input. See the FILE SELECTION sec-
tion for more information.
--exclude-globbing-filelist filename
Like --exclude-filelist but each line of the filelist
will be interpreted according to the same rules as
--include and --exclude.
--exclude-globbing-filelist-stdin
Like --exclude-globbing-filelist, but the list of files
will be read from standard input.
--exclude-other-filesystems
Exclude files on file systems (identified by device
number) other than the file system the root of the
source directory is on.
--exclude-regexp regexp
Exclude files matching the given regexp. Unlike the
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--exclude option, this option does not match files in a
directory it matches. See the FILE SELECTION section
for more information.
--exclude-special-files
Exclude all device files, fifo files, socket files, and
symbolic links.
--exclude-sockets
Exclude all socket files.
--exclude-symbolic-links
Exclude all symbolic links.
--exclude-if-present filename
Exclude directories if filename is present. This option
needs to come before any other include or exclude
options.
--force
Authorize a more drastic modification of a directory
than usual (for instance, when overwriting of a desti-
nation path, or when removing multiple sessions with
--remove-older-than). rdiff-backup will generally tell
you if it needs this. WARNING: You can cause data
loss if you mis-use this option. Furthermore, do NOT
use this option when doing a restore, as it will DELETE
FILES, unless you absolutely know what you are doing.
--group-mapping-file filename
Map group names and ids according the the group mapping
file filename. See the USERS AND GROUPS section for
more information.
--include shellpattern
Similar to --exclude but include matched files instead.
Unlike --exclude, this option will also match parent
directories of matched files (although not necessarily
their contents). See the FILE SELECTION section for
more information.
--include-filelist filename
Like --exclude-filelist, but include the listed files
instead. If filename is handwritten you probably want
--include-globbing-filelist instead. See the FILE
SELECTION section for more information.
--include-filelist-stdin
Like --include-filelist, but read the list of included
files from standard input.
--include-globbing-filelist filename
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Like --include-filelist but each line of the filelist
will be interpreted according to the same rules as
--include and --exclude.
--include-globbing-filelist-stdin
Like --include-globbing-filelist, but the list of files
will be read from standard input.
--include-regexp regexp
Include files matching the regular expression regexp.
Only files explicitly matched by regexp will be
included by this option. See the FILE SELECTION sec-
tion for more information.
--include-special-files
Include all device files, fifo files, socket files, and
symbolic links.
--include-symbolic-links
Include all symbolic links.
--list-at-time time
List the files in the archive that were present at the
given time. If a directory in the archive is speci-
fied, list only the files under that directory.
--list-changed-since time
List the files that have changed in the destination
directory since the given time. See TIME FORMATS for
the format of time. If a directory in the archive is
specified, list only the files under that directory.
This option does not read the source directory; it is
used to compare the contents of two different rdiff-
backup sessions.
-l, --list-increments
List the number and date of partial incremental backups
contained in the specified destination directory. No
backup or restore will take place if this option is
given.
--list-increment-sizes
List the total size of all the increment and mirror
files by time. This may be helpful in deciding how
many increments to keep, and when to --remove-older-
than. Specifying a subdirectory is allowable; then
only the sizes of the mirror and increments pertaining
to that subdirectory will be listed.
--max-file-size size
Exclude files that are larger than the given size in
bytes
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--min-file-size size
Exclude files that are smaller than the given size in
bytes
--never-drop-acls
Exit with error instead of dropping acls or acl
entries. Normally this may happen (with a warning)
because the destination does not support them or
because the relevant user/group names do not exist on
the destination side.
--no-acls
No Access Control Lists - disable backup of ACLs
--no-carbonfile
Disable backup of MacOS X carbonfile information
--no-compare-inode
This option prevents rdiff-backup from flagging a
hardlinked file as changed when its device number
and/or inode changes. This option is useful in situa-
tions where the source filesystem lacks persistent dev-
ice and/or inode numbering. For example, network
filesystems may have mount-to-mount differences in
their device number (but possibly stable inode
numbers); USB/1394 devices may come up at different
device numbers each remount (but would generally have
same inode number); and there are filesystems which
don't even have the same inode numbers from use to use.
Without the option rdiff-backup may generate unneces-
sary numbers of tiny diff files.
--no-compression
Disable the default gzip compression of most of the
.snapshot and .diff increment files stored in the
rdiff-backup-data directory. A backup volume can con-
tain compressed and uncompressed increments, so using
this option inconsistently is fine.
--no-compression-regexp regexp
Do not compress increments based on files whose
filenames match regexp. The default includes many com-
mon audiovisual and archive files, and may be found in
Globals.py.
--no-eas
No Extended Attributes support - disable backup of EAs.
--no-file-statistics
This will disable writing to the filestatistics file
in the rdiff-backup-data directory. rdiff-backup will
run slightly quicker and take up a bit less space.
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--no-hard-links
Don't replicate hard links on destination side. If
many hard-linked files are present, this option can
drastically decrease memory usage. This option is
enabled by default if the backup source or restore des-
tination is running on native Windows.
--null-separator
Use nulls (\0) instead of newlines (\n) as line separa-
tors, which may help when dealing with filenames con-
taining newlines. This affects the expected format of
the files specified by the --{includeexclude}-
filelist[-stdin] switches as well as the format of the
directory statistics file.
--parsable-output
If set, rdiff-backup's output will be tailored for easy
parsing by computers, instead of convenience for
humans. Currently this only applies when listing
increments using the -l or --list-increments switches,
where the time will be given in seconds since the
epoch.
--override-chars-to-quote
If the filesystem to which we are backing up is not
case-sensitive, automatic 'quoting' of characters
occurs. For example, a file 'Developer.doc' will be
converted into ';068eveloper.doc'. To override this
behavior, you need to specify this option.
--preserve-numerical-ids
If set, rdiff-backup will preserve uids/gids instead of
trying to preserve unames and gnames. See the USERS
AND GROUPS section for more information.
--print-statistics
If set, summary statistics will be printed after a suc-
cessful backup. If not set, this information will
still be available from the session statistics file.
See the STATISTICS section for more information.
-r, --restore-as-of restoretime
Restore the specified directory as it was as of
restoretime. See the TIME FORMATS section for more
information on the format of restoretime, and see the
RESTORING section for more information on restoring.
--remote-cmd cmd
Deprecated. Please use --remote-schema instead
--remote-schema schema
Specify an alternate method of connecting to a remote
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computer. This is necessary to get rdiff-backup not to
use ssh for remote backups, or if, for instance,
rdiff-backup is not in the PATH on the remote side.
See the REMOTE OPERATION section for more information.
--remote-tempdir path
Adds the --tempdir option with argument path when
invoking remote instances of rdiff-backup.
--remove-older-than timespec
Remove the incremental backup information in the desti-
nation directory that has been around longer than the
given time. timespec can be either an absolute time,
like "2002-01-04", or a time interval. The time inter-
val is an integer followed by the character s, m, h, D,
W, M, or Y, indicating seconds, minutes, hours, days,
weeks, months, or years respectively, or a number of
these concatenated. For example, 32m means 32 minutes,
and 3W2D10h7s means 3 weeks, 2 days, 10 hours, and 7
seconds. In this context, a month means 30 days, a
year is 365 days, and a day is always 86400 seconds.
rdiff-backup cannot remove-older-than and back up or
restore in a single session. In order to both backup a
directory and remove old files in it, you must run
rdiff-backup twice.
By default, rdiff-backup will only delete information
from one session at a time. To remove two or more ses-
sions at the same time, supply the --force option
(rdiff-backup will tell you if --force is required).
Note that snapshots of deleted files are covered by
this operation. Thus if you deleted a file two weeks
ago, backed up immediately afterwards, and then ran
rdiff-backup with --remove-older-than 10D today, no
trace of that file would remain. Finally, file selec-
tion options such as --include and --exclude don't
affect --remove-older-than.
--restrict path
Require that all file access be inside the given path.
This switch, and the following two, are intended to be
used with the --server switch to provide a bit more
protection when doing automated remote backups. They
are not intended as your only line so please don't do
something silly like allow public access to an rdiff-
backup server run with --restrict-read-only.
--restrict-read-only path
Like --restrict, but also reject all write requests.
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--restrict-update-only path
Like --restrict, but only allow writes as part of an
incremental backup. Requests for other types of writes
(for instance, deleting path) will be rejected.
--server
Enter server mode (not to be invoked directly, but
instead used by another rdiff-backup process on a
remote computer).
--ssh-no-compression
When running ssh, do not use the -C option to enable
compression. --ssh-no-compression is ignored if you
specify a new schema using --remote-schema.
--tempdir path
Sets the directory that rdiff-backup uses for temporary
files to the given path. The environment variables
TMPDIR, TEMP, and TMP can also be used to set the tem-
porary files directory. See the documentation of the
Python tempfile module for more information.
--terminal-verbosity [0-9]
Select which messages will be displayed to the termi-
nal. If missing the level defaults to the verbosity
level.
--test-server
Test for the presence of a compatible rdiff-backup
server as specified in the following host::filename
argument(s). The filename section will be ignored.
--user-mapping-file filename
Map user names and ids according to the user mapping
file filename. See the USERS AND GROUPS section for
more information.
-v[0-9], --verbosity [0-9]
Specify verbosity level (0 is totally silent, 3 is the
default, and 9 is noisiest). This determines how much
is written to the log file.
--verify
This is short for --verify-at-time now
--verify-at-time now
Check all the data in the repository at the given time
by computing the SHA1 hash of all the regular files and
comparing them with the hashes stored in the metadata
file.
-V, --version
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Print the current version and exit
RESTORING
There are two ways to tell rdiff-backup to restore a file or
directory. Firstly, you can run rdiff-backup on a mirror
file and use the -r or --restore-as-of options. Secondly,
you can run it on an increment file.
For example, suppose in the past you have run:
rdiff-backup /usr /usr.backup
to back up the /usr directory into the /usr.backup direc-
tory, and now want a copy of the /usr/local directory the
way it was 3 days ago placed at /usr/local.old.
One way to do this is to run:
rdiff-backup -r 3D /usr.backup/local /usr/local.old
where above the "3D" means 3 days (for other ways to specify
the time, see the TIME FORMATS section). The
/usr.backup/local directory was selected, because that is
the directory containing the current version of /usr/local.
Note that the option to --restore-as-of always specifies an
exact time. (So "3D" refers to the instant 72 hours before
the present.) If there was no backup made at that time,
rdiff-backup restores the state recorded for the previous
backup. For instance, in the above case, if "3D" is used,
and there are only backups from 2 days and 4 days ago,
/usr/local as it was 4 days ago will be restored.
The second way to restore files involves finding the
corresponding increment file. It would be in the
/backup/rdiff-backup-data/increments/usr directory, and its
name would be something like "local.2002-11-09T12:43:53-
04:00.dir" where the time indicates it is from 3 days ago.
Note that the increment files all end in ".diff",
".snapshot", ".dir", or ".missing", where ".missing" just
means that the file didn't exist at that time (finally, some
of these may be gzip-compressed, and have an extra ".gz" to
indicate this). Then running:
rdiff-backup /backup/rdiff-backup-
data/increments/usr/local.
