Dell Compellent and SCSI UNMAP
Dead space reclamation (SCSI UNMAP) Basically the UNMAP command is used when you have Thin Provisioned LUNs, you run it against VMFS 5 datastores, hopefully freeing up some space. This will allow the hosts to correctly report the list of deleted blocks on the datastore to the array. It basically is a space reclamation feature that helps reclaim space left by deleted data. The main reasons you would want to run this on all Thin Provisioned LUNs, would be because of: Storage vMotion, VM snapshots and VM deletion. As even though the VM/Snapshot etc has been deleted it doesn’t mean the array is aware of this! It was disabled in ESXi 5.0, due to various issues and enabled in 5.1 by using […]