Cannot unmount volume ########## because One or more virtual machines are still registered on it.

Products

• VMware vSphere ESXi

Issue/Introduction

Attempts to remove datastore from vCenter fail with error Cannot unmount volume ########## because One or more virtual machines are still registered on it.

Environment

VMware vSphere ESXi (All Versions)

Cause

VM in the environment is still configured to make use of the datastore:

Resolution

Need to do either of the following options:

• If the disks are still needed in the datastore then reconnect datastore to the host and migrate the disks off the datastore.
• If the disks are no longer needed edit the VM configuration to remove the disks.
  or
• Unregister the VM's from the inventory and make sure no objects are referencing the datastore.

Once the datastore is no longer referenced by the VM configuration it can be removed from vCenter.

Additional Information

How to detach a LUN device from ESXi hosts