UNMAP is a SCSI command that can be issued to the storage array by a host system to reclaim space on a thin volume after disk blocks have been deleted by an application or OS. Note: For the procedure ...UNMAP is a SCSI command that can be issued to the storage array by a host system to reclaim space on a thin volume after disk blocks have been deleted by an application or OS. Note: For the procedure to enable thin reporting on legacy volumes after you have upgraded to 08.25.05 or later, see article: How to enable UNMAP on existing Thin Volumes for VMware ESXi
