Nadrek (3/31/2011)
For those with RAID; how many actually run consistency checks on a regular basis, to detect single drive corruption?...
I would also note that planning for regular failure is both very expensive and very limiting; most products don't support truly transparent high availability with 0% downtime at all. Big mainframe hardware (and perhaps midrange systems) does; commodity x86 based hardware and software typically doesn't, with a few exceptions.
0% downtime is extremely expensive. One needs to be realistic. Most apps can tolerate occasional downtimes of varying degrees, and it's a lot less expensive to evaluate those needs realistically.
Interestingly, we used to have a clustered RAID SQL2000 installation. Every system failure we had was in the RAID control system which meant that the clustering did us no good whatsoever in the downtime area. (Fortunately the RAIDs did not lose data during those failures). We have a mirrored system now on completely separate hardware.
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-- FORTRAN manual for Xerox Computers --