Creating a Backup Chain v2.6

A backup chain is the set of backups consisting of a full backup and all of its successive incremental backups. Tracing back on the parent backups of all incremental backups in the chain eventually leads back to that single, full backup.

It is possible to have a multi-forked backup chain, which is two or more successive lines of incremental backups, all of which begin with the same, full backup. Thus, within the chain there is a backup that serves as the parent of more than one incremental backup.

Since restoration of an incremental backup is dependent upon first restoring the full backup, then all successive incremental backups up to, and including the incremental backup specified by the RESTORE subcommand, it is crucial to note the following:

• Deletion or corruption of the full backup destroys the entire backup chain. It is not possible to restore any of the incremental backups that were part of that chain.
• Deletion or corruption of an incremental backup within the chain results in the inability to restore any incremental backup that was added to that successive line of backups following the deleted or corrupted backup. The full backup and incremental backups prior to the deleted or corrupted backup can still be restored.

The actions of retention policy management are applied to the full backup and all of its successive incremental backups within the chain in an identical manner as if they were one backup. Thus, use of retention policy management does not result in the breakup of a backup chain.

See the EDB Backup and Recovery Reference Guide, available at the EDB website for examples of creating a backup chain and restoring an incremental backup.