VP Snap control commands are the same as with Solutions Enabler 7 and Enginuity 5876, enabling users to use their existing VMAX VP Snap scripts. However, there are several behavioral differences that need to be understood when preparing volumes and monitoring sessions. The following behaviors apply to VP Snap in PowerMaxOS and HYPERMAX OS:
- All VP Snap target volumes from a specific source do not need to be associated to the same SRP.
- VP Snap target volumes can be moved across SRPs while sessions are active. Non-shared allocations are moved.
- As source tracks are updated, the Protected Track counts do not decrement.
- As source tracks are updated when the session is active, the preserved point-in-time tracks for the VP Snap sessions are stored in the SRP of the source volume, even if the target volume is in a different SRP. Only changed tracks on the target volume are stored in the target SRP.
- Shared allocation counts in Solutions Enabler and Unisphere do not apply due to the way that shared allocations are handled in PowerMaxOS and HYPERMAX OS. These counters always show zero.
- VP Snap target volumes are not deallocated when the sessions are terminated. If the target volume is in a separate SRP from the source volume, any allocations that reside in the source SRP after terminating are relocated to the target SRP by a FAST compliance move.
Note: See Appendix C: Monitoring the copy process for information about monitoring the copy process of Mirror and Clone sessions.