Usage scenarios

Recovery from USB

Prepare your rescue media using

rear format /dev/sdX

It will be labeled REAR-000. The /etc/rear/local.conf can be as simple as:


Run rear -v mkbackup to create the rescue media including the archive of the Operating System.

Rescue system

Relax-and-Recover will not automatically add itself to the Grub bootloader. It copies itself to your /boot folder.

To enable this, add


to your local configuration.

The entry in the bootloader is password protected. The default password is REAR. Change it in your own local.conf


Storing on a central NFS server

The most straightforward way to store your DR images is using a central NFS server. The configuration below will store both a backup and the rescue CD in a directory on the share.


Backup integration

Relax-and-Recover integrates with various backup solutions. Your backup software takes care of backing up all system files, Relax-and-Recover recreates the filesystems and starts the file restore.

Currently Bacula, Bareos, SEP Sesam, HP DataProtector, CommVault Galaxy, Symantec NetBackup, EMC NetWorker (Legato), FDR/Upstream, and IBM Tivoli Storage Manager are supported.

The following /etc/rear/local.conf uses a USB stick for the rescue system and Bacula for backups. Multiple systems can use the USB stick since the size of the rescue system is probably less than 40M. It relies on your Bacula infrastructure to restore all files.


Monitoring integration

Relax-and-Recover integrates with your monitoring. The rear checklayout command will tell you if the most recent rescue environment deviates from your storage configuration (e.g. LVM changes, filesystem resized, …)

In good Unix tradition rear checklayout returns 0 if your system is in sync with your rescue image. A return code of 1 should lead to a red light in your monitoring screen because a new rescue image is needed. Create a rescue image and the next time rear checklayout runs, it will return 0 again, and your monitoring will switch to green.

You can also automate the creation of rescue images by adding a cron job for /usr/sbin/rear checklayout || /usr/sbin/rear mkrescue. And make sure the OUTPUT_URL points to a central location for storing your rescue images. By default, a rear installation via a package manager will automatically install a cron entry - see:

 # cat /etc/cron.d/rear
 30 1 * * * root /usr/sbin/rear checklayout || /usr/sbin/rear mkrescue

Furthermore, rear will write an exit code to the /var/log/messages file which you could use to search via an integrated monitoring system (search for the rear keyword).