Rsnapshot

Installation

rsnapshot can be installed using yum when extras, rpmfusion, rpmforge etc. repositories are also configured properly.

Configuration

rsnapshot uses '/etc/rsnapshot.conf' file for configuration. Two very important points about configuration file are:

• All paths must end with / and all backup destination should be relative
• Various fields in file are separated using Tab. Space does not separates fields

Recommended configuration

Following configuration is recommended for Cent-OS / Linux users:

• Configure 'snapshot_root' as absolute path on current system. Note that in case of remote backups rnapshot is always run on backup server and not on client to be backuped up.
• Leave cmd_cp, cmd_rm, cmd_rsync, as it is
• Uncomment cmd_ssh
• Set proper backup intervals. The order of interval lines is important. More frequent backup lines should come first. Example configuration is

interval        hourly  6
interval        daily   7
interval        weekly  4
interval        monthly 3

• Decrease loglevel to 2
• Enable link_dest by setting its value to 1
• Setup local backups such as

backup_script	/bin/date "+ backup of officepc started at %c" > start.txt		officepc/officepc_start/
backup		/etc/			officepc/
backup		/home/			officepc/
backup		/root/			officepc/
backup		/documents/		officepc/
backup		/mnt/data1/ebooks/	officepc/
backup		/mnt/data1/songs/	officepc/
backup		/mnt/data1/personal/	officepc/
backup_script	/bin/date "+ backup of officepc completed at %c" > end.txt		officepc/officepc_end/

• Setup remote backups, such as

backup_script	/bin/date "+ backup of officepc started at %c" > start.txt	officepc/officepc_start/
backup		root@10.5.1.222:/documents/		officepc/	+rsync_long_args=--bwlimit=1000
backup		root@10.5.1.222:/etc/			officepc/	+rsync_long_args=--bwlimit=1000
backup		root@10.5.1.222:/home/			officepc/	+rsync_long_args=--bwlimit=1000	
backup		root@10.5.1.222:/root/			officepc/	+rsync_long_args=--bwlimit=1000	
backup		root@10.5.1.222:/mnt/data1/ebooks/	officepc/	+rsync_long_args=--bwlimit=1000
backup		root@10.5.1.222:/mnt/data1/songs/	officepc/	+rsync_long_args=--bwlimit=1000
backup		root@10.5.1.222:/mnt/data1/personal/	officepc/	+rsync_long_args=--bwlimit=1000
backup_script	/bin/date "+ backup of officepc completed at %c" > start.txt	officepc/officepc_end/

Database dump configuration

Example configuration that dumps mysql databases during backup is

backup_script	/usr/bin/sshpass -p <password> mysqldump -u root -p wikidb_notes | bzip2  > /documents/room-documents/documents/databases/mysql/notes_wiki/wikidb_notes.sql.bz2		officepc/.ignore1/
backup_script	/usr/bin/sshpass -p <password> mysqldump -u root -p wikidb_res | bzip2  > /documents/room-documents/documents/databases/mysql/research_wiki/wikidb_res.sql.bz2		officepc/.ignore2/
backup_script	/usr/bin/sshpass -p <password> mysqldump -u root -p wikidb_readme | bzip2  > /documents/room-documents/documents/databases/mysql/readme_wiki/wikidb_readme.sql.bz2		officepc/.ignore3/

Note that in this case rsnapshot.conf file should be readable only by root user.

Important points

• In backup_script parameters to commands are separated by space which is not a problem as rsnapshot only uses tab as field separator. Hence we can give script commands which require arguments without any problem
• Backup specific options can be specified in optional fourth field in backup. '+' in such cases indicates keep existing options and add these additional options with them. Without '+' original options will be removed and given options will be the only options
• Final folder used as target of backup_script should be unique. Hence following is not acceptable

backup_script     echo "hello" > hello.txt     pc1/folder1/
backup_script     echo "hi"  > hi.txt          pc2/folder1/

as both destinations end with folder1, even though parent folder is different. This is most likely bug and may get corrected in future.

• Backup script is run in temp folder and contents of temp folder are then synced with specified destination folder
• We can run commands which require password like mysql_dump with ssh-pass.
• Commands can be run remotely using backup_script as 'ssh root@10.5.1.222 "ls > /root/ls.txt"' with destination folder ignore1 or similar. Then contents of /root can be backed up to get contents of ls.txt. This when used in combination with sshpass can allow backup_script to take database dumps in specific folders, before those folders are backed up.

Crontab configuration

One can configure crontab using 'crontab -e' command to take backups at specified intervals automatically. Sample crontab configuration is

0 */4 * * *       /usr/bin/rsnapshot hourly
45 23 * * *       /usr/bin/rsnapshot daily
30 23 * * 0       /usr/bin/rsnapshot weekly
15 23 1 * *       /usr/bin/rsnapshot monthly

Other options

We can use 'rsnapshot du' or 'rsnapshot du <folder_name>' to get information about space occupied by particular folder

Restoration

Root user can restore files or directory structures using cp or rsync. To allow normal users to restore their files (and only their files) we can use following steps:

1. Create a parent folder accessible only by root using something like

   mkdir /private
   chmod 700 /private

2. Make snapshot folder for users readable by everyone using

   mkdir /private/snapshots
   chmod 755 /private/snapshots

3. Then share snapshot folder using NFS as explained in Configuring basic NFSv3 server
4. Then mount exported NFS partitions in some folder on system from where users can access only their own backups and not backups of other users

Steps learned from official rsnapshot how to at time of writing at http://rsnapshot.org/howto/1.2/rsnapshot-HOWTO.en.html#configuration