When you unmount a datastore, it remains intact, but can no longer be seen from the hosts that you specify. The datastore continues to appear on other hosts, where it remains mounted.

Do not perform any configuration operations that might result in I/O to the datastore while the unmount is in progress.


vSphere HA heartbeating does not prevent you from unmounting the datastore. If a datastore is used for heartbeating, unmounting it might cause the host to fail and restart any active virtual machine. If the heartbeating check fails, the vSphere Client displays a warning.

Before unmounting VMFS datastores, make sure that the following prerequisites are met:

No virtual machines reside on the datastore.

The datastore is not part of a datastore cluster.

The datastore is not managed by Storage DRS.

Storage I/O control is disabled for this datastore.

The datastore is not used for vSphere HA heartbeating.


Display the datastores.


Right-click the datastore to unmount and select Unmount.


If the datastore is shared, specify which hosts should no longer access the datastore.


Deselect the hosts on which you want to keep the datastore mounted.

By default, all hosts are selected.


Click Next.


Review the list of hosts from which to unmount the datastore, and click Finish.


Confirm that you want to unmount the datastore.

After you unmount a VMFS datastore, the datastore becomes inactive and is dimmed in the host's datastore list. An unmounted NFS datastore no longer appears on the list.


The datastore that is unmounted from some hosts while being mounted on others, is shown as active in the Datastores and Datastore Clusters view.