After the backup
First and foremost, verify that the backup actually happened.
Many systems ship with backup scripts that verify the tape after the backup has been performed. Some suggested methods of tape verification:
- Set up a UNIX script that creates an extra file. Make sure it's the first file on the backup tape. This file should contain the time and date stamp of when the backup was performed. This gives you at-a-glance verification.
- Set up a script to send UNIX mail to root. Set it up so that the message contains a list of files that were written to the backup tape. The System Administrator can compare the "backup" mail each day and against the tape to make sure the two reconcile.
- Look for a file with the current time and date. When a UNIX system writes to a file, it normally updates the time and date stamp on that file. For example, say a user entered new customers (ARCUST) to the system prior to the backup at the end of business Friday, July 1. If the date on ARCUST is Friday, July 1, the backup was successful.
Tape Labeling
Make sure you develop a system for labeling tapes to prevent overwrites.
Off-Site Protection
Store your backup tapes off-site. This provides an additional level of protection from natural disasters. At the minimum, store your weekly and monthly backups off-site.