Explanation/Reference:
Explanation:
To reclaim unused storage blocks on a VMFS datastore for a thin-provisioned device, run this command:
esxcli storage vmfs unmap --volume-label=volume_label|--volume-uuid=volume_uuid --reclaim- unit=number The command takes these options:
-l|--volume-label=volume_label

The label of the VMFS volume to UNMAP. This is a mandatory argument. If you specify this argument,

do not use -u|--volume-uuid=volume_uuid.
-u|--volume-uuid=volume_uuid

The UUID of the VMFS volume to UNMAP. This is a mandatory argument. If you specify this argument, do not use -l|--volume-label=volume_label.
-n|--reclaim-unit=number

The number of VMFS blocks to UNMAP per iteration. This is an optional argument. If it is not specified, the command uses a default value of 200.
Reference: https://kb.vmware.com/selfservice/microsites/search.do?
language=en_US&cmd=displayKC&externalId=2057513