David Robinson ([EMAIL PROTECTED]) wrote on 8 June 1999 09:59:
>A perfect setup would be to have each side of the mirror on a
>different SCSI bus/SCSI card. that way no matter what happened to
>either side the kernel would keep running.. even if the SCSI card
>died and you were using two SCSI cards.
Yes, this is a big problem with raid. The cards are
single-points-of-failure. And usually you can't have one disk per
controller, particularly with raid5, because there aren't enough
slots. If a card with two disks dies you lost everything, if the array
gets out of sync. It's quite difficult to find/afford special boards
with many slots or channels, at least here.
The good side is that usually the machine locks completely when the
bus hangs, so that you have to hard-reset. This is not exactly
high-availability, but at least the array doesn't get out of sync!
