- Lets assume my both the arrays are consistently replicating the data then what could be the issue? - This isn't possible without a replication solution that supports this (recoverpoint may be such a solution, as it handles replication rather than the array). If you have 2 arrays that support cross array consistency groups and can be managed with a single SRA this would work, otherwise not. You're talking about 2 different arrays working together to replicate multiple LUNs and maintain write order consistency between them. I don't see how this would be possible without something sitting in front of both arrays providing this capability, and even then I'm not positive it's possible.
- Is SRM uses any mechanism to check the consistency even if single array is used? - SRM is not a replication solution. It relies on the array to tell it what LUNs/datastores are in consistency groups and then makes sure that all of the disks of a VM are located on the same consistency group.
- What if single array has multiple datastores and each one created from different lun and then VM is using the multiple datastores coming from the same array, then how replication consistency is checked in this case? - See above. Array consistency groups are defined when configuring replication between arrays. For details on how consistency groups are created and operated check with your array vendor.
