If your VMFS datastore requires more space, increase the datastore capacity. You can dynamically increase the capacity by growing a datastore extent or by adding an extent.

Use one of the following methods to increase the datastore capacity:

  • Dynamically grow any expandable datastore extent, so that it fills the available adjacent capacity. The extent is considered expandable when the underlying storage device has free space immediately after the extent.
  • Dynamically add the extent. The datastore can span over up to 32 extents with the size of each extent of more than 2 TB, yet appear as a single volume. The spanned VMFS datastore can use any or all its extents at any time. It does not need to fill up a particular extent before using the next one.
    Note: Datastores that support only the hardware assisted locking, also called the atomic test and set (ATS) mechanism, cannot span over non-ATS devices. For more information, see vSphere Storage.

Increase an Existing VMFS Datastore in the VMware Host Client

When you need to add virtual machines to a datastore, or when the virtual machines running on a datastore require more space, you can dynamically increase the capacity of a VMFS datastore.

If a shared datastore has powered on virtual machines and becomes 100% full, you can increase the datastore's capacity only from the host that the powered on virtual machines are registered on.


  1. Click Storage in the VMware Host Client inventory and click Datastores.
  2. Click New datastore.
  3. On the Select creation type page, click Add an extent to existing VMFS datastore and click Next.
  4. On the Select datastore page, select the datastore to expand and click Next.
  5. On the Select device page, select a device to create the new VMFS partition on and click Next.
  6. On the Select partitioning options page, select how to partition the device and click Next.
    Option Description
    Use Full Disk

    It shows you all the free space that is available on the device.


    Click the Free space bar and use the horizontal scroller to partition the device.

  7. On the Ready to complete page, review the configuration details and click Finish.