[CLUE-Tech] RAID-5

[Dan Harris]

>I'd sure like to watch (demo at school) this automagic repair in action.
>Should I be able to power down cleanly, remove a drive, put in a physically
>identical drive and have it recreate the drive I removed?
>
>Adam, thanks for your feedback on this.
>
>  
>
This feature depends on how smart your RAID controller is.  I used to 
give this demo to prospective clients years ago when the PCI Mylex 960 
card was all the rage.  I would start a large database transaction 
script and let all the blinky lights go nuts..  Then I'd yank out a 
drive (hot-swap of course) with no impact whatsoever (even on speed) to 
the application.  I'd explain that a drive just died and stick in a 
fresh drive.  Immediately the controller detected a new drive, 
initialized it and becan resynching.  This never once required an 
interruption in application or a reboot.

So, if you had to reboot for any reason after removing your drive, I'd 
point the finger at your RAID controller, not at the idea of RAID in 
general.  I've managed dozens of mission-critical systems and anything 
less than RAID-5 for key servers is just not acceptable.  It works..

-Dan