drobo is in data protection, mac is frozen

I replaced one 1TB drive with a 2TB drive and after a number of days, my drobo (1st gen) finished data protection. I then replaced another 1TB drive with a 2TB drive and it’s been five days doing its data protection again. As of this morning the drobo had about 120 hours to go, down from 181 a few days ago. The drobo is one of three attached to a mac mini.

This morning I was copying files from one of the other drobos to another mac mini via the local lan. I now find that the mini with the drobos seems frozen. I can’t get the monitor to wake up. I’ve also found that the drobo has dropped off Finder’s “Shared” list on one of my other macs. The mini’s lights are still on and the drobo going through data protection has its drive lights still blinking as they have been.

In the past, when something like this has happened, I would shut down the mini using the power button and then start it up again. A recent thread suggests that we shouldn’t unplug a drobo when it is going through data protection. Aside from just letting the mini go on as it is (whether frozen or not) for what may be another 5 days, is there anything else I might do? I assume I should not hard reboot it - right?

BTW - when a drobo is doing data protection, is it doing that on its own? Or must the attached mac be on as well?

protection is internal to the drobo, its perfectly safe to shut down the computer, drobo will not go into standby though as it usually would, it will finish protection before shutting itself down

Thanks for the advice. I rebooted and drobo is still performing data protection - no problems.