Thin Image Advanced S-VOLs can be paired with secondary layer S-VOLs. First layer (L1) S-VOLs can also be paired with secondary layer (L2) S-VOLs. A maximum of 64 layers can be created, and a maximum of 1,024 S-VOLs can be used for a P-VOL. In this case, the snapshot tree is cascaded.
L2 to L64 pairs are called cascaded pairs. The following figure illustrates the configuration of cascaded snapshot trees.
- The volume in the top layer of the snapshot tree (P-VOL of the L1 pair) is the root volume.
- Volumes between the root and leaf volumes are node volumes.
- Volumes in the bottom layer of the snapshot tree are leaf volumes.
In this document, a cascade configuration represents a cascaded snapshot tree using Thin Image Advanced. A configuration where a P-VOL of a Thin Image Advanced pair shares volumes with S-VOLs of other replication software applications is not referred to as a cascade configuration.