Understanding the Recovery Sets

A recovery set is a storage setting where a group of recovery points backed-up over a specified period is stored as one set. A recovery set includes a series of backups, starting with a full backup, and then followed by a number of incremental, verify, or full backups. You can specify the number of recovery sets to retain.

The Recovery Set Settings ensures periodic maintenance of recovery sets. When the specified limit is exceeded, the oldest recovery set is deleted. The following values define the default, minimum, and maximum recovery sets in Arcserve UDP Agent (Linux):

Default: 2

Minimum: 1

Maximum number of recovery sets: 100

Notes:

• After reaching the retention count, the merge job gets triggered and the oldest Recovery Set gets deleted.
• If you want to delete a recovery set to save backup storage space, reduce the number of retained sets and Backup Server automatically deletes the oldest recovery set. Do not attempt to delete the recovery set manually.

Example Set 1:

• Full
• Incremental
• Incremental
• Verify
• Incremental

Example Set 2:

• Full
• Incremental
• Full
• Incremental

A full backup is required to start a new recovery set. The backup that starts the set will be automatically converted to a full backup, even if there is no full backup configured or scheduled to be performed at that time. After the recovery set setting is changed (for example, changing the recovery set starting point from the first backup of Monday to the first backup of Thursday), the starting point of existing recovery sets will not be changed.

Note: An incomplete recovery set is not counted when calculating an existing recovery set. A recovery set is considered complete only when the starting backup of the next recovery set is created.

Example 1 - Retain 1 Recovery Set:

• Specify the number of recovery sets to retain as 1.
• Backup Server deletes the first recovery set when the third recovery set Full backup is completed.
• Note: Even if you choose to retain only one recovery set, you need space for at least two full backups.

Example 2 - Retain 2 Recovery Sets:

• Specify the number of recovery sets to retain as 2.
• Backup Server deletes the first recovery set when the fourth recovery set full backup is completed. This ensures that when the first backup is deleted and the fourth recovery set Full backup is completed, you still have two recovery sets (recovery set 2 and recovery set 3) available on disk.

Example 3 - Retain 3 Recovery Sets:

• Specify the number of recovery sets to retain as 3.
• Backup Server deletes the first recovery set when the fifth recovery set Full backup is completed.
• The backup start time is 6:00 AM, August 20, 2012.
• An incremental backup runs every 12 hours.
• A new recovery set starts on Friday. By default, the first backup job on Friday will be the start of the new recovery set.
• You want to retain 3 recovery sets.

With the above configuration, an incremental backup runs at 6:00 AM and 6:00 PM every day. The first recovery set is created when the first backup (must be a full backup) is taken. Then the first full backup is marked as the starting backup of the recovery set. When the backup scheduled at 6:00 AM on Friday runs, it will be converted to a full backup and marked as the starting backup of the recovery set.

Note: If you want to run the backup job repeatedly until the end of day, set the schedule until 12:00 AM. For example, to run backup job every 15 minutes for the entire day, set the schedule from 12:00 AM to 12:00 AM, every 15 minutes.