I had a controller card flake out on me, and thought I lost my array (mini heart attack). Fortunately, I realized it was three drives (parity, cache, and one array drive) on the card.
(Slight) problem once I got things fixed, my parity was disabled and I had to rebuild parity even though I had not changed anything in the array from before the problem. What I did:
1. PANIC (array wouldn't start, missing parity and cache drive (not assigned) and drive 7 (showed ID)
2. Determine problem, fix problem, reboot.
3. Array starts with parity disabled (red X on parity drive)
4. Stop array, restart...parity disabled.
5. Reboot. Array starts...parity disabled.
6. Stop array. Unassign parity. Re-assign parity (no option for 'parity is valid'). Restart array, parity rebuild.
Not a huge issue, as rebuilding parity took about an hour longer than checking parity.
One remaining issue, Windows no longer sees the unRaid by name on the network. Can still access by IP. (edit - this seems to be a Windows issue, don't know why it started suddenly)