Increase size of VMFS datastore

You might sometimes want to dynamically increase the capacity of a VMFS datastore, for example, when a VMFS datastore was not sized adequately or a virtual machine experiences unexpected growth.

Two methods are available to increase the size of a VMFS datastore in vSphere:

  • add an extent to the VMFS datastore – you can add an extent (a partition on a LUN) to any VMFS datastore. You can add up to 32 extents (LUNs) to the datastore, up to 64TB.
  • expand the VMFS datastore – you can increase the size of the datastore in its extent. Extents must have free space immediately after them. A LUN can be expanded any number of times, up to 64TB.

You don’t need to power off virtual machines when using either method of increasing the VMFS datastore capacity.


A VMFS datastore can only be expanded and not shrinked.
Geek University 2021