Verifying Backups

There are many tales of tape based backups where the database administrator had to cut a sorry figure when data recovery time came. The tapes had not been formated and none of the scheduled backups wrote anything on the tapes!

Hard Disk based backups minimise chances of such errors. ZRM for MySQL goes one step beyond this and provides you with direct commands to verify the backup.

Verification of Backup Images

ZRM for MySQL can verify the backup images using backup checksums. Best practice is to verify the backup images for all backup sets on a regular basis.

• To verify the backup images of the last backup run for the backup set backup:

# mysql-zrm --action verify-backup --backup-set backup

• To verify the specific backup run of backup set backup:

# mysql-zrm --action verify-backup --backup-set backup --no-quiet \
           --source-directory /var/lib/mysql-zrm/backup/20060829093000
INFO: Verification successful

mysql-zrm returns 0 if the backup verification is successful.

• Example: Verifying all backup images. Backup set BackupSet1 backup on "12 Jul 2006" has verification failures.

# mysql-zrm --action verify-backup --no-quiet
ERROR: checksum for file /var/lib/mysql-zrm/BackupSet1/20060712140704/backup.sql does not match
ERROR: Errors found during verification

ZRM for MySQL has a reporter utility which can greatly assist you to check the outcome of the backup run.