How Thin Image uses V-VOLs

V-VOLs are virtual volumes that do not have any physical storage space.

Thin Image uses V-VOLs (V-VOLs of provisioning type Snapshot) or DP-VOL as V-VOLs. Thin Image V-VOLs and DP-VOLs are referred to as virtual volumes (V-VOLs). Use DP-VOLs to create cascaded or cloned pairs. Use Thin Image V-VOLs to create snapshot pairs. Note that you can use DP-VOLs to cascade snapshot pairs.

Thin Image uses V-VOLs to access snapshot data from hosts or clone pairs, so if you are using a storage system that does this (creates snapshot pairs or clone pairs), V-VOLs are required to assign an S-VOL to snapshot data. If the storage system or snapshot pair (a pair with the snapshot attribute) does not need to access snapshot data from hosts, V-VOLs are not necessary.

You can release the V-VOLs that are being used as Thin Image S-VOLs from assignment of snapshot data. Released V-VOLs can be assigned to other snapshot data. However, you cannot release allocation of V-VOLs used as node volumes to snapshot data or allocate the V-VOL to different snapshot data. Also, you cannot release allocation of V-VOLs which are being used for the S-VOL of a clone pair to snapshot data, or allocate it to different snapshot data.

You cannot release definitions of V-VOLs if the V-VOLs are being used as Thin Image secondary volumes; you must first release the Thin Image pairs that are using the V-VOLs.