What increment chains are

An increment chain is a series of incremental backups of the same path. Because you can specify any level of backup at any time, you must understand increment chains to be able to perform backups and restores effectively. You can perform 31 levels of incremental backup operations.

There are two types of increment chains:

Incremental backups are based on the most recent lower-level backup. For example, the sequence of backup levels 0, 2, 3, 1, 4 provides two increment chains: 0, 2, 3 and 0, 1, 4. The following table explains the bases of the incremental backups:

Backup order Increment level Increment chain Base Files backed up
1 0 Both Files on the storage system All files in the backup path
2 2 0, 2, 3 Level-0 backup Files in the backup path created since the level-0 backup
3 3 0, 2, 3 Level-2 backup Files in the backup path created since the level-2 backup
4 1 0, 1, 4 Level-0 backup, because this is the most recent level that is lower than the level-1 backup Files in the backup path created since the level-0 backup, including files that are in the level-2 and level-3 backups
5 4 0, 1, 4 The level-1 backup, because it is a lower level and is more recent than the level-0, level-2, or level-3 backups Files created since the level-1 backup