Unix Backup and Recovery

Homegrown Bare-Metal Recovery

If you are in a heterogeneous environment with other, different Unix systems such as Sun, HP, or IBM, you might want to use a consistent method for bare-metal recovery among all your machines. This section shows how the homegrown recovery procedure described in the previous chapter can be applied, providing a complete custom bare-metal recovery plan for Compaq Unix. In addition, Digital provides a very powerful proprietary system for bare-metal recovery that has many advantages and is covered in the next section.

Before Disaster Strikes

Like most bare-metal recovery procedures, you are required to do a few things up front in order to protect yourself from such a disaster:

1. If you are going to replace the root disk with another one without reinstalling the OS, you will have to partition the new disk the same way the old one was partitioned. The only way you are going to know that is to save this partitioning information. (It also would help if all your OS disks were partitioned in the same way.) You can use disklabel to print the current partition information:

   # disklabel -r 
                           raw-disk-device

2. Save the /etc/fstab file. (This file is very useful when trying to rebuild a system from scratch.)

3. If you are using AdvFS, save the /etc/fdmns directory structure:

   # tar cf /
                           nfsdrive
                           /fdmns.
                           systemname
                           .tar /etc/fdmns

4. Send this information to a centralized system, or more than one centralized system, so you can access it if any server becomes unavailable. One of the best ...