Suppose that I have a nix system whose filesystems are entirely supported by two drives in a RAID 1. If I were to breakdown that RAID, could I then use one of the disks to recreate the system on separate hardware? Does anybody use such a scheme as a way of building systems?
SnapOverflow
I have done it under Solaris (Solstice Disk Suite) so I can say it's definitely possible to do. It will be very much implementation-dependent, though, so you need to say what Unix you're using, and whether it's hardware of software RAID.
It may work under unixish systems so long as you remember to change all the system-specific information like IP/hostname/etc
You'll run into problems with anything that puts guids into device identifiers or partition tables or filesystem descriptions.
In general, it seems like the kind of thing you can do but that you'd be better off using something like fog or similar automated provisioning system that does what you want directly as opposed to using a side-effect of something else.
I've used this method to clone identical hardware. 1 becomes 2 becomes 4 becomes 8.... You let the mirrors run overnight each day and you've got 16 servers by Friday and you didn't have to do anything more complex than swap drives around in the evening.
Label the disks carefully!
As someone else said, main thing to watch out for with this approach is GUIDs. You can use tune2fs on an ext(x) FS on Linux to solve that problem by updating the GUID on each partition, though. Even then, it won't really matter until you try to do something fancy (like two years from now, consolidating two boxen into one by putting both their hard drives in the same chassis).
The only other thing I can think of that would go sideways is your eth(x) settings, if they have HWADDR or MACADDR in them. HWADDR should fail gracefully, but MACADDR will happily put twenty of the same MAC addresses on the same network, which--to put it mildly--will NOT fail gracefully.