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- Write Same (Zero): Also known as Block zeroing. This primitive is primarily used for the ESXi host to instruct the storage to zero out eagerzeroedthick VMDKs.
- XCOPY (Extended Copy): Also known as Full copy. Instead of the ESXi host performing the work of reading and writing blocks of data, this primitive allows the host to instruct the array to copy data which saves SAN bandwidth. This operation is typically used when cloning VMs.
- Atomic Test & Set (ATS): Also known as Hardware accelerated locking. This primitive replaces SCSI-2 reservations to increase VMFS scalability with changing metadata on VMFS datastores. With SCSI-2 reservations, the entire volume had to be locked, and all other hosts in the cluster had to wait while that ESXi host changed metadata. The hardware accelerated locking primitive allows a host to lock only the metadata on disk it needs, not hampering I/O from other hosts while the operation is performed.
- UNMAP: Also known as dead space reclamation. This primitive uses the SCSI UNMAP command to release blocks that are no longer in use back to the array. For example, after deleting a VM, the ESXi host issues a series of commands to the PowerStore array to indicate that it is no longer using certain blocks within a volume. This capacity is returned to the pool so that it can be reused.