This topic is relevant if you are using vSAN datastores. Prior to vSphere with vSAN 6.7U1, there is no space reclamation support. Starting with 6.7U1, vSAN space reclamation is supported with the vCenter UNMAP feature on vSAN datastores. It is disabled by default.

Procedure

  1. Check that the UNMAP feature is enabled in the ESXi host.
    Run the following commands from the command line:
    esxcfg-advcfg -g /VSAN/GuestUnmap

    The value of the "GuestUnmap" option is 0.

    esxcfg-advcfg -g /VSAN/Unmap

    The value of the "Unmap" option is 1.

  2. Enable guest UNMAP in all ESXi hosts.
    Run the following command:
    esxcfg-advcfg -s 1 /VSAN/GuestUnmap

    Then, check the UNMAP feature for the guest operating system. Run the following command:

    esxcfg-advcfg -g /VSAN/GuestUnmap
    The value of the GuestUnmap option is 1.
  3. Enable the UNMAP feature in vCenter Server.
    Run the following RVC command:
    vsan.unmap_support <cluster> -e