Um Joe, 'popping the drive and slipping in another' is not supported. :-) You may very well end up with a requirement to do an IOA cache reclaim which may (or may not) cause the system to flag the ASP as *EMPTYThis is what happens all the time. Even if I power down, when I insert a new drive it doesn't recognize it until I actually rebuild the disk. I see "FAILED" but with the old serial number until I rebuild the RAID set. After it's done, it sees the new serial number.
However in that situation if you have successfully completed a couple of SAVE 21s then I'd do just that. End the system to restricted condition. Let it sit for 5 or 10 minutes to be sure nothing was left in the caches and give it a go. Note that in this case the system likely wouldn't see the new serial number of the drive since as far as it's concerned the drive simply went silent and then came back. But I'd give it 60-40 that it would work.
Does your disk cage have the plastic light pipes that show the LEDs on the disk cage backplane? If it does you can concurrently maintain your system.
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