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Unable to grow or expand a VMFS volume or datastore (1017662)

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When you try to grow or expand a VMFS volume by clicking Increase option, there are no available devices to select.

Note: For additional symptoms and errors, see the Additional Information section. 


To increase the capacity(grow or extend) of a VMFS datastore successfully, rescan the storage adapters to ensure that Extent Device list contains updated list and then use the Increase option. 


To increase the capacity of a VMFS datastore:

  1. In vCenter Server, select the Datastores view.
  2. Select the datastore you want to grow and identify the host that has more virtual machines running on it.
  3. Open another vSphere client that connects directly to the ESX/ESXi host.
  4. Go to Configuration > Storage adapters and perform a rescan. 
  5. Go to Configuration > Storage, click the datastore that you want to grow, and click Properties.
  6. Ensure that the new size of the device is listed in the Extent Device list. If the increased size does not reflect, review the changes on the storage array and rescan again.
  7. Click Increase.
  8. Select a device from the list of storage devices for which the Expandable = Yes and click Next.
  9. Set the capacity for the extent. The default capacity for the extent is the entire free space on the storage device.

    Note: VMware recommends you to use the default setting.

  10. Click Next.
  11. In vCenter Server, right-click the cluster that sees the expanded datastore, and click Rescan for Datastores
  12. If there are other hosts that see the expanded datastore, perform a rescan on these hosts also.

Note: If you do not see the datastore after step 6 and/or 7, try to perform the same steps by connecting to the stand alone ESXi host directly.

Additional Information

You experience these additional symptoms: 
  • When you click Increase, a device is listed but does not have Expandable = Yes
  • When you select the volume and click Next, you see the error:
failed to update disk partition information

  • If a shared datastore powers on virtual machines and becomes 100% full, increase the datastores capacity only from the host on which the powered-on virtual machines are registered.
  • As an alternative workaround, free up additional storage space by performing a Storage vMotion to migrate some of the virtual machines to a datastore with more available space.


increase-datastore, increase-size, expand vmfs

See Also

Update History

07/13/2011 - Added note about increasing the size of storage arrays. 04/08/2013 - Added vCenter Server 5.1.x and ESXi 5.1.x to Products 04/24/2-13 - Added alternative workaround in the Additional Information section

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