Title: Bare Metal Recovery Software
Course: CIS 208: Linux/UNIX III: Intermediate System Administration, Networking, and Security ~ For IGNITE Review > Section: Learning Modules

Bare Metal Recovery Software

A bare metal backup is an archive of a computer system which will allow the operating system to be restored on the host after a complete hard drive failure.  After the defective hard drives have been replaced, the data is recovered directly to formatted or unformatted disks.

Many bare metal recovery programs exist, both proprietary and open source.  If selecting new software, be sure that the program will support your entire Linux environment, since some programs only support a limited set of filesystems and/or partitioning schemes.

Several features differentiate available programs.

- A key one is the ability to do live backups, preventing the necessity to plan down time for a production server.
- Another feature is the ability to restore on dissimilar hard drives and/or to change the filesystem type at the time of recovery.  While all programs will support archiving to a network location, some allow the data to be saved in iso files which can be burned to cd or dvd media.

Whichever solution is chosen, it is important to test and fully document the restore procedure.

- Start by creating an archive and ensure that there were no significant errors.
- Find a similar server which can be used for testing or create a virtual machine with specs similar to the original server.
- Perform a recovery and create documentation.  Note that the recovered server may try to use the same IP address as the original, so it is best to bring up the test server disconnected from the network.
- Examine the recovered server carefully, noting items which need to be updated such as the /etc/fstab file or the /etc/sysconfig/network-scripts/ifcfg-* files.  If data files are regularly backed up, restore the latest version.
- Check if anything special needs to be done for java apps and/or databases.
- Document these post-recovery procedures.

The documentation should be clear enough that a junior sysadmin or a low-level consultant would be able to follow the instructions.  This will ensure that the right procedures are followed, even if they need to be performed during a stressful outage or at odd hours.  Ideally the documentation will identify a person who will be the contact for the organization.  This will let the administrator perform the duties uninterrupted, provided that the contact is given timely updates.