Dell Solutions Enabler 10.0.0 TimeFinder SnapVX CLI User Guide

Source device requirements for consistent snapshots:

By default, all SnapVX snapshots are consistent with the database when created and established. Depending on the state of the devices at the time of the snapshot, SnapVX pauses I/O to ensure there are no writes to the source device while the snapshot is created. When the activation completes, writes are resumed and the target device contains a consistent production database copy of the source device at the time of activation.

• All devices must be R1 or R2; a mixture of R1 and R2 devices is not supported.
• A mixture of R1 and non-SRDF devices is allowed. The R1 devices can be a mixture of RW and NR on the SRDF link.
• A mixture of R2 and non-RDF devices is allowed if the R2 devices are NR on the SRDF link.
• A mixture of R1 and R21 devices is allowed if the R1->R21 is NR on the SRDF link.
• A mixture of R2 and R21 devices is allowed, if the following criteria is met:
  • R1->R2 and R1->R21 devices are all RW on the SRDF link.
  • R1->R2 and R1->R21 are all NR on the SRDF link.

If the source devices do not meet these criteria then the snapshot cannot be created unless a force flag is used. Using a force flag forces the snapshot to be created; however, the consistency of the snapshot cannot be guaranteed.