Specs for server

[Alan Cox]

> If you have hardware RAID, a drive failure shouldn't take the system
> down at all.

Often not true. It's a lot better with SATA than PATA or SCSI. There are
various ways failed devices can jam up busses and its not unknown for
them to trigger controller bugs even in "brand name" setups. With SCSI
busses it was all too common for a failed drive to jam an entire bus.

Ideally you want the two halves of the mirror on different controllers
but it depends how much resilience you need. As you get more serious it
gets more and more pricy until you end up with the "mirrored servers
separated by at least twice the crater size of a worst case airbus a380
crash on the data centre"

and there *are* people who work to that spec ;)

Alan