That’s what I was looking for. The problem with booting a live distro is that the machine is headless and, while connecting a monitor and keyboard is easier than pulling it out of the rack, getting to the back side of my rack is still a bit of a job.
In the end, there was a third drive that was totally missing in action. Wasn’t even showing upon Disks. So I ended up pulling the box out of the rack and opening it up anyway.
Thanks for the help, guys!