The small business that I do sysadmin work for on the side uses a mid-2011 Mac Mini Server (running 10.7 Lion) as a fileserver and FileMaker database host. Its 2 750gb HDDs are RAID 1'd together, and it Time Machine backups over USB to a RAID 1 array of 2 1 TB disks.
I set it up about a year and a half ago and had no problems with it until a few months ago. I opened Disk Utility to find that the RAID had degraded and that it was only running on one disk. I went out and bought another 750gb HDD, installed it, and rebuilt the array.
Everything was fine for a week - then, the array degraded again. I rebuilt the array and it was fine again until last week - when again, the array degraded. It keeps degrading on the same device - disk1 has always been fine, but disk2 keeps degrading, regardless of what physical hard drive is in there. I don't think it's a hardware issue.
What should I do? I would reinstall OSX, but I've never restored a backup from Time Machine before and I'm not sure what to expect - if things go sideways, I woud have to reconfigure a lot of stuff, including about 10 user accounts and network shares and stuff (not to mention the FileMaker configuration stuff). This is just a side thing for me, and I really don't want to burn up a Friday-night-to-Monday-morning-nonstop weekend scenario on this because something went wrong and I lost everything.