You can use thin-provisioned storage arrays with ESXi.

The ESXi host integrates with block-based storage and performs these tasks:

  • The host can recognize underlying thin-provisioned LUNs and monitor their space use to avoid running out of physical space. The LUN space might change if, for example, your VMFS datastore expands or if you use Storage vMotion to migrate virtual machines to the thin-provisioned LUN. The host warns you about breaches in physical LUN space and about out-of-space conditions.

  • The host can run the automatic T10 unmap command from VMFS6 and VM guest operating systems to reclaim unused space from the array. VMFS5 supports a manual space reclamation method.


ESXi does not support enabling and disabling of thin provisioning on a storage device.


To use the thin provisioning reporting and space reclamation features, follow these requirements:

  • Use an appropriate ESXi version.

    Table 1. ESXi Versions and Thin Provisioning Support

    Supported thin provisioning components

    ESXi 6.0 and earlier

    ESXi 6.5

    Thin provisioning



    Unmap command originating form VMFS

    Manual for VMFS5. Use esxcli storage vmfs unmap.

    Automatic for VMFS6

    Unmap command originating from guest OS

    Yes. Limited support.

    Yes (VMFS6)

  • Use storage systems that support T10-based vSphere Storage APIs - Array Integration (VAAI), including thin provisioning and space reclamation. For information, contact your storage provider and check the VMware Compatibility Guide.