You can use the Space Reclaimer feature to reclaim space left by recently freed blocks in VMDK files located in NFS datastores when you use SnapDrive for Windows with SnapManager for Virtual Infrastructure in an ESX environment.
You can run Space Reclaimer on VMDK files using SnapDrive MMC and sdcli.exe.
Space reclamation is not supported on sparse extents and VMFS datastores.
If SnapManager for Virtual Infrastructure is not available, SnapDrive is unable to discover VMDKs and, therefore, cannot reclaim space on VMDK files.