Skip to main content
Pure Technical Services

Troubleshooting: Failed to Unmount and Detach Datastore with vSphere Plugin

Currently viewing public documentation. Please login to access the full scope of documentation.


Problem:  When customers try to Destroy a DataStore, they might get this alert:

“Failed to unmount and detach datastore. Please ensure that there are no registered VMs on this datastore and try again. Then it’s 1/2 deleted and inaccessible in vcenter.”  With Pure vSphere plugin 4.2.x.

Example Error:


Please check these in your environment.

Before unmounting a LUN, ensure that:

  • If the LUN is being used as a VMFS datastore, all objects, (such as virtual machines, snapshots, and templates) stored on the VMFS datastore are unregistered or moved to another datastore.
  • Note: All CD/DVD images located on the VMFS datastore must also be unregistered from the virtual machines.
  • The datastore is not used for vSphere HA heartbeat.
  • The datastore is not part of a datastore cluster.

Ref Kb:

  • Please also ensure that this Datasore only uses Pure Luns.
  • If this datastore used as heartbeat datastore, you may need to switch that role. (Consult Vmware for this operation).
  • If there is any host in maintenance mode, make sure to rescan storage/hba for that hosts manually.