While backups are a daily occurrence, restorations are normally a less frequent event. However, restorations are inevitable; they will be necessary, so it is best to be prepared.
The important thing to do is to look at the various restoration scenarios detailed throughout this section and determine ways to test your ability to actually carry them out. And keep in mind that the hardest one to test is also the most critical one.
188.8.131.52. Restoring From Bare Metal
The phrase "restoring from bare metal" is a system administrator's way of describing the process of restoring a complete system backup onto a computer with absolutely no data of any kind on it -- no operating system, no applications, nothing.
Overall, there are two basic approaches to bare metal restorations:
- Reinstall, followed by restore
Here the base operating system is installed just as if a brand-new computer were being initially set up. Once the operating system is in place and configured properly, the remaining disk drives can be partitioned and formatted, and all backups restored from backup media.
- System recovery disks
A system recovery disk is bootable media of some kind (often a CD-ROM) that contains a minimal system environment, able to perform most basic system administration tasks. The recovery environment contains the necessary utilities to partition and format disk drives, the device drivers necessary to access the backup device, and the software necessary to restore data from the backup media.
Some computers have the ability to create bootable backup tapes and to actually boot from them to start the restoration process. However, this capability is not available to all computers. Most notably, computers based on the PC architecture do not lend themselves to this approach.