Multiplicity is a very basic frontend to
rdiff-backup. Its goal is to
provide easy management of multiple independant backup tasks.
rsync (incremental file tree copies to save bandwidth), hard links (to save backup space),
ssh (to transmit data) and a very handy incremental machinery (to allow us to go back in time through our backups).
multiplicity is a script aimed at easing the management of backup jobs. It is a basic frontend to
rdiff-backup. It consists of the main scipt and a directory filled with task files. Each task file defines a backup source, a backup target and various other parameters.
A task file must be in the configuration directory (may be set on the command line and defaults to
/etc/multiplicity). It should be named with a
.task suffix (read dot task). The following configuration values are accepted in a task file :
run_this: This globally enables or disables the task file. Any value other than
yesdisables the task file.
max_age: delete files deleted more than this value ago and file history older than this value. This parameter is directly passed to
source_root: the root directory of the files you want to backup.
target_root: the root directory where you want to backup your files.
include_file: a full path (or relative to the configuration directory) to a file that lists what files to include in the backup. As the default is to backup all files, this is only usefull if the files you list here would have been excluded regarding the
exclude_fileconfiguration. See next dot.
exclude_file: files to exclude from the backup.
pre: execute this in the
bashshell before executing the backup task. This must fit on one line.
post: execute this after the backup task. This must fit on one line.
Example task file
run_this no max_age 185D source_root / target_root /backup exclude_file local.exclude pre mount -o remount,rw /backup post mount -o remount,ro /backup
Carefull, what separates configuration keys from configuration values is a real tabulation
\t. I should probably fix this, one day.
Example exclude file
/var /proc /bin *.log
Global pre and post scripts
There is also the possibility of running global pre and post scripts, i.e scripts that run before and after the task batch. Those are to put in the configuration directory under the names of
1 2 3 4 5 6
#!/bin/bash # This script is run before the backup task batch begins. # Feel free to customize it # Dump mysql data to a file mysqldump --user root --password=pass --all-databases > /var/backups/mysqldata base.dump
multiplicity accepts the following command-line options :
confdiras the configuration directory, i. e. where to look for task files.
-v: Be verbose. Default is really quiet.
-h: Display a (very) short help summary.
You can browse multiplicity's source online or grab a snapshot archive on the same page.
You can get the source using
$ git clone http://sousmonlit.zincube.net/~niol/repositories.git/multiplicity
multiplicity may run in any directory, but it was made to be run in the following way :
- Create the directory
taskfiles. You can re-use the example from the distribution.
- Drop the
multiplicityscript in a
crondirectory if applicable, for example on Debian, I dropped it in
/etc/cron.dailyto make it run once a day. After a couple of days, you may want to put
VERBOSEto a zero value to stop getting cron report emails.
Installation (my setup)
This section describes my setup. The goal is to backup from
Password-less SSH logins
The first thing to do is to setup password-less SSH logins for the
root user to the hosts you want to backup to (or the hosts you want to backup from, but I'll describe here how to use remote backup hosts to backup to). First create a key pair for this purpose.
# cd # mkdir .ssh # chmod 700 .ssh # ssh-keygen -t rsa -f ~/.ssh/id_rsa (no passphrase)
If, like me, you have aliases for your hosts and special ports, you may want to use a
.ssh/config file :
Host backup1 User backupuser Port 400 HostName backupfool.foo1.org Host backup2 User backupuser Port 400 HostName backupguy.foo2.org
Now, copy your IDs to the remote hosts (repeat for
# ssh-copy-id -i ~/.ssh/id_rsa.pub backupuser@backup1 Password:
Now you should be able to login with the local
root user on
# ssh backup1 (no password prompted) firstname.lastname@example.org $
So, here is the plan : I want to backup several selected directories to a dedicated
/backup partition and I want to backup only a part of those selected directories to the remote hosts, especially avoiding to send to the remote hosts my passwords and my emails.
I run a mySQL server on
ripley. Thus, I use
/etc/multiplicity/pre.sh to dump the database contents to a file :
#!/bin/bash mysqldump --user root --password=unbreakable_password --all-databases > /var/backups/mysqldatabase.dump
Then I described
/etc/multiplicity/local.include which is a list of the things on
ripley that I want to backup :
/etc - **tmp /home/niol /root - /var/fileserv/enac/album**tn /var/fileserv/enac/album/**jpg /var/backups /var/spool/minimalist /var/www - **
Basically, I want to backup
/etc, no files that end with
tmp, my personal directory, stuff on my ftp server except thumbnails directories,
/var/backups, my mailing list manager config, my web directory and nothing else. Check the
backup-manager manual page for more information on file inclusions and exclusions (globbing filelists).
But when backing up to a remot host, I want to omit some files (the contents of the ftp server which is too big and the ones that contain clear text passwords) which I described in
/var/fileserv/ **id_rsa **id_dsa **identity **gpg* **.bash_history **.fetchmailrc **.gnubiffrc /etc/ssh/ssh_host*key /etc/multiplicity/pre.sh /home/niol/fromannalee/home/niol/.gaim /home/niol/fromannalee/home/niol/.mozilla /var/www/sousmonlit/sql.conf.php
(I really don't like clear-text-stored passwords…)
This was the most difficult part bescause you need to know what is on your computer. But now, the only remaining thing is to describe multiplicity tasks.
/etc/multiplicity/local.task (the local backup):
run_this yes max_age 185D source_root / target_root /backup/local include_file local.include pre mount -o remount,rw /backup post mount -o remount,ro /backup
/etc/multiplicity/backup1.task (the order of
include_file is important):
run_this yes max_age 10D source_root / target_root backup1::/home/backupuser/fromripley/ exclude_file remote.exclude include_file local.include
/etc/multiplicity/backup2.task (this is the second friend I send my backups to, just in case):
run_this yes max_age 10D source_root / target_root backup2::/home/backupuser/fromripley/ exclude_file remote.exclude include_file local.include
This should be self explainatory and this should show what is
Running the script
The first run should be a bit long :
# /etc/cron.daily/multiplicity -v
From now on, you can check on the remote hosts which files have been backed up :
# ssh backup1 email@example.com $ ls fromripley etc home rdiff-backup-data root var
You also may check what increments are available :
firstname.lastname@example.org $ rdiff-backup -l fromripley Found 9 increments: increments.2005-12-27T06:30:54+01:00.dir Tue Dec 27 06:30:54 2005 increments.2005-12-28T06:31:53+01:00.dir Wed Dec 28 06:31:53 2005 increments.2005-12-29T06:31:03+01:00.dir Thu Dec 29 06:31:03 2005 increments.2005-12-30T06:32:27+01:00.dir Fri Dec 30 06:32:27 2005 increments.2005-12-31T06:33:26+01:00.dir Sat Dec 31 06:33:26 2005 increments.2006-01-01T06:32:10+01:00.dir Sun Jan 1 06:32:10 2006 increments.2006-01-02T06:31:25+01:00.dir Mon Jan 2 06:31:25 2006 increments.2006-01-03T06:30:41+01:00.dir Tue Jan 3 06:30:41 2006 increments.2006-01-04T06:31:11+01:00.dir Wed Jan 4 06:31:11 2006 Current mirror: Thu Jan 5 06:31:08 2006
rdiff-backup beginners guide to know how to recover an old file…