Growing or expanding a VMFS volume or datastore

      Symptoms

When you try to grow or expand a VMFS volume, you experience these symptoms:

·    One or more storage devices have been increased in capacity from the storage array.

·    When you click Increase, there are no available devices to select.

·    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

Resolution

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 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 is not reflected, 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 column is 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. VMware recommends you to use the default setting.

10.   Click Next.

11.   After the process completes, go to 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.


Source VMware KB