On 25/06/2010 18:22, Jon Green wrote:
On 25/06/2010 17:28, Clive George wrote:
On 25/06/2010 17:03, Jon Green wrote:

I suspect that Mike meant more than just the drives. If you're dealing
with mission-critical data, it's imperative to keep a hot spare RAID box
too, in secure storage away from the building, so that you can bring up
the data set ASAP after a RAID main board failure. There's absolutely no
guarantee that the drive set will work together in a different model or
make -- in fact, it's pretty-much certain they won't.

Once you're doing that you may as well have the second RAID (or rather
filer) mirrored from the first, and have a truly hot DR system.

That'll work...so long as the backup RAID isn't totalled by the same
fire or power surge that nargled the primary!

I did make the assumption that the backup RAID was at a different site :-)

It won't absolve you from having the hot (well, warm, since it's not
connected or running) spare and the backups off-site for full disaster
recovery.

So now you've got three sets of kit! Primary, local mirror, off-site hot
spare.)

Nah, just two - Primary, off-site hot spare/mirror.