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5 Operation : 5.2 Managing Backups Using a Retention Policy : 5.2.5 Managing Incremental Backups

The retention policy rules are applied to full backups. Determining when a backup is obsolete by the redundancy retention policy is based solely by the number of full backups. All incremental backups are excluded from the comparison count against the retention_policy setting for the maximum number of backups. Determining when a backup is obsolete by the recovery window retention policy is based solely by the backup date/time of the full backup. The backup date/times of any successive incremental backups in the chain are ignored when comparing with the recovery window.
The actions applied by the MANAGE and DELETE subcommands on a full backup are applied to all incremental backups in the chain in the same manner.
The following are some specific points regarding the MANAGE and DELETE subcommands on incremental backups:
When the MANAGE subcommand is invoked, the status applied to the full backup is also applied to all successive incremental backups in the chain.
The MANAGE subcommand with the -c { keep | nokeep } option cannot specify the backup identifier or backup name of an incremental backup with -i backup option. The -i backup option can only specify the backup identifier or backup name of a full backup. The option -i all is allowed to be used. When the MANAGE subcommand with the -c { keep | nokeep } option is applied to a full backup, the same status change is made to all incremental backups in the chain.
The DELETE subcommand with the -s server -i backup options is allowed to specify the backup identifier or backup name of an incremental backup in which case that incremental backup along with all its successive incremental backups are deleted, thus shortening that backup chain.
When the redundancy retention policy is used and the MANAGE subcommand is invoked, the status of the oldest, active, full backups are changed to obsolete if the number of full backups exceeds the maximum number specified by the retention_policy parameter in the BART configuration file.
See Section 5.2.3.1 for information on the redundancy retention policy.
When determining the number of backups that exceeds the number specified by the retention_policy parameter, only full backups are counted for the comparison. The number of incremental backups is not included in the count for this comparison against the retention_policy parameter setting.
The following examples show usage of the MANAGE and DELETE subcommands when a 3 backup redundancy retention policy is in effect as shown by the following server configuration:
The following is the current set of backups. (In these examples, some columns have been omitted from the SHOW-BACKUPS output in order to display the relevant information in a more observable manner.)
Backup chain: 1481749619582 => 1481749651927 => 1481749673603 => 1481749696905
The MANAGE subcommand is invoked as shown by the following:
Second backup chain: 1481749997807 => 1481750098924
The MANAGE subcommand is invoked, but now with a total of four active full backups.
Invoking the MANAGE subcommand with the -d option deletes the entire obsolete backup chain.
The following section provides an example using the recovery window retention policy. Example usage of the MANAGE subcommand with other options along with usage of the DELETE subcommand are shown in this next section.
When the recovery window retention policy is used and the MANAGE subcommand is invoked, the status of active, full backups are changed to obsolete if the date/time of the full backup is outside of the recovery window (that is, the full backup date/time is prior to the start of the recovery window as defined the by current date/time when the MANAGE subcommand is invoked, and then going back in time by the amount of time set by the retention_policy parameter in the BART configuration file.
See Section 5.2.3.2 for information on the recovery window retention policy.
The following examples show usage of the MANAGE and DELETE subcommands when a 1-day recovery window retention policy is in effect as shown by the following server configuration:
The following is the current set of backups. (In these examples, some columns have been omitted from the SHOW-BACKUPS output in order to display the relevant information in a more observable manner.)
First backup chain: 1481552078404 => 1481553088053 => 1481553914533 => 1481554802918 => 1481559014359
Second backup chain: 1481553651165 => 1481554203288 => 1481559303348
The MANAGE subcommand is invoked when the first full backup 1481552078404 falls out of the recovery window. When the MANAGE subcommand is invoked, it is 2016-12-13 09:20:03 EST, thus making the start of the 1-day recovery window at 2016-12-12 09:20:03 EST exactly one day earlier. This backup was taken at 2016-12-12 09:14:39 EST, which is about 5 ½ minutes before the start of the recovery window, thus making the backup obsolete.
The following example shows how the entire backup chain is changed back to active status by invoking the MANAGE subcommand with the -c nokeep option on the full backup of the chain.
The following example shows usage of the DELETE subcommand on an incremental backup. The specified incremental backup 1481554802918 in the first backup chain as well as its successive incremental backup 1481559014359 are deleted.
The results show that incremental backup 1481554802918 as well as its successive backup 1481559014359 are no longer listed by the SHOW-BACKUPS subcommand.
The MANAGE subcommand is invoked again. This time both backup chains are marked obsolete since the full backups of both chains fall out of the start of the recovery window, which is now 2016-12-12 09:55:03 EST.
The following shows usage of the MANAGE subcommand with the -c keep option to keep a backup chain indefinitely. The MANAGE subcommand with the -c keep option must specify the backup identifier or backup name of the full backup of the chain and not any incremental backup.
The following now displays the full backup 1481553651165 of the backup chain and its successive incremental backups 1481554203288 and 1481559303348 changed to keep status.
Finally, the MANAGE subcommand with the -d option is used to delete the obsolete backup chain.

5 Operation : 5.2 Managing Backups Using a Retention Policy : 5.2.5 Managing Incremental Backups

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