Monitoring Backup History Using oncheck

You can monitor the history of your last full-system backup using oncheck.

Execute oncheck -pr to display reserved-page information for the root dbspace. The last pair of reserved pages contains the following information for the most recent backup:

• Backup level (0, 1, or 2)
• Effective date and time of the backup
• Time stamp describing when the backup began (expressed as a decimal)
• ID number of the logical log that was current when the backup began
• Physical location in the logical log of the checkpoint record (that was written when the backup began)

The effective date and time of the backup equals the date and time of the checkpoint that this backup took as its starting point. This date and time could differ markedly from the time when the backup process was started.

For example, when no one accessed the database server after Tuesday at 7 P.M., and you create a backup Wednesday morning, the effective date and time for that backup is Tuesday night, the time of the last checkpoint. In other words, when there has been no activity after the last checkpoint, the database server does not perform another checkpoint at the start of the backup.