[lug] raid

[D. Stimits]

j davis wrote:
> Hello,
>  So i sprung for 4 18 gig scsi drives. 2 are 7200rpm one is 10000 rpm and
> one is 15000 rpm....so i would like to take 3 of the disk and make a 
> raid 5 array.
> is it ok to have different speed disk in a (hardware)raid array?
> 
> thanks,
> jd

There is no technical reason to stop you, it'll work fine, but having 
slightly different specs can result in far less optimum throughput than 
with matched disks. But for raid 5, those in series can be matched, and 
the one doing checksum would be nice as the 15krpm disk (till you lose a 
drive). You could use the 10k for separate swap, plus other things, like 
/tmp/, and gain other benefits. Raid 5 of course is not for performance 
reasons anyway, it is for the case of disk failure, so you will probably 
be reasonably happy with it (you'd be more happy with 3 of the disks 
being matched, and the 4th as the 15krpm).

D. Stimits, stimits AT attbi.com