The Dell EMC TimeFinder SnapVX engine uses the Redirect-On-Write (ROW) technology that creates snapshots by storing changed tracks (deltas) directly on the storage resource pool (SRP) of the source device.
A single source volume can have a maximum of 256 snapshots.
Target Devices
Starting from Commvault 11.19, you can choose the target device that you want to mount snapshots. You can also use the automatic selection that is available in earlier versions.
Auto Selection of Target Devices
When you use auto selection of target devices, there is no need to specify a target device and a source or target pairs. During the map operation of a snapshot, a target volume is selected or created automatically by the EMC SMI-S layer, which is then mapped to the host computer for snapshot data access.
If a new target device is created for the mapping operation, that target device is not deleted after the unmap operation. The reason for not deleting the target device is to reuse it for subsequent map operations.
Target Device Selection from User-Specified Storage Group
If you need to restrict the selection of target devices to a particular set of devices, then you must create a dummy storage group and add the thin devices (TDEVs) that can be selected as target devices to that storage group.