Increasing VMFS Datastore Capacity

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.