So we have a HP MSA 2042 and a Dell Compellent 2020 as our main prod storage. The issue we appear to be having is with auto space reclaim under VMware 6.5
In the Compellent we have some SSD disks and 10K SAS. From what I have been told, the Data page size is auto allocated based on the type of disk,ie for our SSD pool, its been given a Data page size of 512k, for our 10K SAS, its been given 2MB.
Am I correct in assuming that auto space reclamation will never work for the pool allocated a 2MB data page size back at the array?
Now according to the HCL, our array supports this. According to Dell, I can't change the Data page size to under 1MB for the SAS pool, and it will cause a massive loss of use-able space if I did that.
I was told by Dell that if I migrate a VM from say Datastore A, to Datastore B, lets say each DS is a separate VOL back at the array, even though the space is not reclaimed from the Datastore A VOL, it will know it can "use" that space still on subsequent writes. Does that sound correct? Because it doesn't to me.
Any help would be much appreciated.