As far as I'm aware, you just replaced like any other faulted drive.

Always done that and never had any problems.

If your vault disk has user lun's carved on it, then it will use a hot spare.  If you dont have any user lun's, then you can just swap out the disk for a new one.  You must check the event logs to make sure the new disks has finished rebuilding before continuing with another.

And the reason it disables cache is becuase the first 4 disks contain the SP Images.  IF there was a system crash and it needed to shut down, it would right what ws in cache to disks 0 and 2(first disk of each SP).  It would then be mirrored to disks 1 and 3.  when one of those disks has a problem, it will disable system cache becuase there is a possibility that it might not be able to write to the vault disks .

question:

although hot spare is invoked and enabled.

still with flare 30 and 31 cache is disabled?

why?