As I was working through my VCAP5-DCA studies, I was at the point where I had to mask a LUN. I typically don’t perform this function on my hosts in my enterprise environment, but rather, let my storage admins look after those details.
But I am working on my home lab and this is a requirement for the DCA exam, so I was all in. I was at the point where I had to reclaim the device and the following error appeared.
I was puzzled at first thinking that nothing is actually using this device in my home lab – but it turns out I was wrong. I gave it some thought and since I had HA running, is it possible that this device is being used as a heartbeat datastore.
The answer was YES
I removed the datastore-LUNMASK as one of the heartbeat datastores, ran through my procedure and it work! I hope this helps other folks that may run into this situation.