rdiff-backup examples
Sections
- Backing up
- Restoring
- Deleting older files
- File selection with include/exclude options
- Getting information about the backup directory
- Miscellaneous other commands
Backing up
Simplest case---backup local directory
foo
to local directorybar
.bar
will end up a copy offoo
, except it will contain the directory foo/rdiff-backup-data, which will allow rdiff-backup to restore previous states.rdiff-backup foo bar
-
Simple remote case---backup directory
/some/local-dir
to the directory/whatever/remote-dir
on the machine hostname.net. It uses ssh to open the necessary pipe to the remote copy of rdiff-backup. Just like the above except one directory is on a remote computer.rdiff-backup /some/local-dir hostname.net::/whatever/remote-dir
-
This time the source directory is remote and the destination is local. Also, we have specified the username on the remote host (by default ssh will attempt to log you in with the same username you have on the local host).
rdiff-backup user@hostname.net::/remote-dir local-dir
-
It is even possible for both the source and destination directories to be on other machines. Below we have also added the
-v5
switch for greater verbosity (verbosity settings go from 0 to 9, with 3 as the default), and the--print-statistics
switch so some statistics will be displayed at the end (even without this switch, the statistics will still be saved in therdiff-backup-data
directory).rdiff-backup -v5 --print-statistics user1@host1::/source-dir user2@host2::/dest-dir
Restoring
Suppose earlier we have run
rdiff-backup foo bar
, with both foo and bar local. We accidentally deletedfoo/dir
and now want to restore it frombar/dir
.
That's right, since rdiff-backup makes a mirror, we can retrieve files using standard commands likecp -a bar/dir foo/dir
cp
.For the rest of the examples in the section, we will assume that the user has backed up with the command
rdiff-backup local-dir host.net::/remote-dir
. Of course, in all these examples it would be equally possible to have the source being remote and the backup directory local.In this case we can't use
cp
to copyinghost.net::remote-dir/file
tolocal-dir/file
because they are on different machines. We can get rdiff-backup to restore the current version of that file using either of these::
Therdiff-backup --restore-as-of now host.net::/remote-dir/file local-dir/file
rdiff-backup -r now host.net::/remote-dir/file local-dir/file--restore-as-of
(or-r
for short) switch tells rdiff-backup to restore instead of back up, and thenow
option indicates the current time.But the main advantage of rdiff-backup is that it keeps version history. This command restores
host.net::/remote-dir/file
as it was 10 days ago into a new location/tmp/file
.
Other acceptable time strings includerdiff-backup -r 10D host.net::/remote-dir/file /tmp/file
5m4s
(5 minutes and 4 seconds) and2002-03-05
(March 5th, 2002). For more information, see the TIME FORMATS section of the manual page.-
Finally, we can use rdiff-backup to restore directory from an increment file. Increment files are stored in
host.net::/remote-dir/rdiff-backup-data/increments
and hold the previous versions of changed files. If you specify one directly:
rdiff-backup will tell from the filename that it is an rdiff-backup increment file and thus enter restore mode. Above the restored version is written tordiff-backup host.net::/remote-dir/rdiff-backup-data/increments/file.2003-03-05T12:21:41-07:00.diff.gz local-dir/file
local-dir/file
.
Deleting older files
Although rdiff-backup tries to save space by only storing file
differences, eventually space may run out in the destination
directory. rdiff-backup's --remove-older-than
mode can
be used to delete older increments.
This section assumes that rdiff-backup has been used in the past to
back up to host.net::/remote-dir
, but all commands would
work locally too, if the hostname were ommitted.
-
This commands deletes all information concerning file versions which have not been current for 2 weeks:
Note that an existing file which hasn't changed for a year will still be preserved. But a file which was deleted 15 days ago cannot be restored after this command is run.rdiff-backup --remove-older-than 2W host.net::/remote-dir
-
As when restoring, there are a variety of ways to specify the time. The
20B
below tells rdiff-backup to only preserve information from the last 20 rdiff-backup sessions. (nnB
syntax is only available in versions after 0.13.1.)rdiff-backup --remove-older-than 20B host.net::/remote-dir
File selection with include/exclude options
Sometimes you don't want to back up all files. The various
--include
and --exclude
options can be used
to select exactly which files to back up. See the man page for a list
of all the options and their definitions.
In this example we exclude
/mnt/backup
to avoid an infinite loop.
(Actually rdiff-backup can automatically detect simple loops like the one above.) This is just an example, in reality it would be important to excluderdiff-backup --exclude /mnt/backup / /mnt/backup
/proc
as well.This example is more realistic. We have excluded
/proc
,/tmp
, and/mnt
./proc
in particular should never be backed up. Also, the source directory happens to be remote.rdiff-backup --exclude /tmp --exclude /mnt --exclude /proc user@host.net::/ /backup/host.net
Multiple include and exclude options take precedence in the order they are given. The following command would back up
/usr/local/bin
but not/usr/bin
.rdiff-backup --include /usr/local --exclude /usr / host.net::/backup
rdiff-backup uses rsync-like wildcards, where
**
matches any path and*
matches any path without a/
in it. Thus this command:
backs up only therdiff-backup --include /usr/local --include /var --exclude '**' / /backup
/usr/local
and/var
directories. The single quotes''
are not part of rdiff-backup and are only used because many shells will expand**
.Here is a more complicated example:
The above command will back up any file ending inrdiff-backup --include '**txt' --exclude /usr/local/games --include /usr/local --exclude /usr --exclude /backup --exclude /proc / /backup
txt
, even/usr/local/games/pong/scores.txt
because that include has highest precedence. The contents of the directory/usr/local/bin
will get backed up, but not/usr/share
or/usr/local/games/pong
.rdiff-backup can also accept a list of files to be backed up. If the file
include-list
contains these two lines:
Then this command:/var /usr/bin/gzip
would only back up the filesrdiff-backup --include-filelist include-list --exclude '**' / /backup
/var
,/usr
,/usr/bin
, and/usr/bin/gzip
, but not/var/log
or/usr/bin/gunzip
. Note that this differs from the--include
option, since--include /var
would also match/var/log
.The same file list can both include and exclude files. If we create a file called
include-list
that contains these lines:
Then the following command will do exactly the same thing as the complicated example two above.**txt - /usr/local/games /usr/local - /usr - /backup - /proc
Above we have usedrdiff-backup --include-globbing-filelist include-list / /backup
--include-globbing-filelist
instead of--include-filelist
so that the lines would be interpreted as if they were specified on the command line. Otherwise, for instance,**txt
would be considered the name of a file, not a globbing string.
Getting information about the backup directory
The following examples assume that you have runrdiff-backup
in-dir out-dir
in the past.
This command finds all new or old files which contain the string
frobniz
.
rdiff-backup doesn't obscure the names of files at all, so often using traditional tools work well.find out-dir -name '*frobniz*'
Either of these equivalent commands lists the times of the available versions of the file
out-dir/file
. It may be useful if you need to restore an older version ofin-dir/file
but aren't sure which one.rdiff-backup --list-increments out-dir/file
rdiff-backup -l out-dir/fileThe following command lists all the files under
out-dir/subdir
which has changed in the last 5 days.rdiff-backup --list-changed-since 5D out-dir/subdir
This command lists all the files that were present in
out-dir/subdir
5 days ago. This includes files that have not changed recently as well as those that have been deleted in the last 5 days.rdiff-backup --list-at-time 5D out-dir/subdir
The first command below compares the current files in out-dir (which is on a remote computer) with the files in in-dir, displaying which ones have changed. The second command is similar but compares in-dir to out-dir as it was 2 weeks ago.
rdiff-backup --compare in-dir user@host::out-dir
rdiff-backup --compare-at-time 2W in-dir user@host::out-dir- rdiff-backup writes one statistics file per session to the
out-dir/rdiff-backup-data
directory. An average of the files can be displayed using the--calculate-average
option and specifying the statistics files to use.rdiff-backup --calculate-average out-dir/rdiff-backup-data/session_statistics*
Miscellaneous other commands
If you are having problems connecting to a remote host, the
--test-server
command may be useful. This command simply verifies that there is a working rdiff-backup server on the remote side.rdiff-backup --test-server hostname.net::/ignored