[Discuss] raid issues

[adler at stephenadler.com (Stephen Adler)]

Guys,

I'm in the process of ordering a new server for my work and I want to 
get one which can handle 16 to 24 drives. But with so much disk capacity 
I was wondering what people to do make the file systems secure. In the 
past I've used either raid 5 or raid 6 arrays. The idea being that if 1 
(raid 5) or 2 (raid 6) drives died, you were OK, all you had to do was 
replace the drives and the rebuild would occur and you were fine.

But then one day I had 4 drives fail at once. It wasn't the drives that 
failed, but the disk controller. I had added a 4 port SATA card to my 
server so that I could add for more drives to my server. So now with 
getting a server with such large drive capacity, I'm wondering of all 
this raid stuff just gives on the warm fuzzies, but in fact you are just 
as vulnerable since you controllers can go and knock out half your 
drives (or whatever).

Any comments on how to deal with say a 16 disks and what's the current 
lore on making large redundant disk arrays?

Thanks in advance!

Cheers. Steve.