This is very helpful - thank you.

I have unmounted and detached the datastore and confirmed that they display as dismounted and detached ( via Get-Datastore storename | Get-DataStoreMountInfo).

When i remove the assignment from my SAN (HP P4000) we still get alerts along the line

[VMware vCenter - Alarm alarm.StorageConnectivityAlarm] Alarm 'Cannot connect to storage' on vmware2.company.com changed from Red to Green.

And in vSphere client they show with the red alarm.

I tried rescanning first, but, same effect.

Is this the expected outcome - i was hoping for a "quieter" disconnect.  Does this happen to anyone else?