Jon Nelson wrote:
http://en.wikipedia.org/wiki/RAID5 It's really very good.
Hehe, I know - been there already. It was very informative, but I didn't see much on the two drive failure situation.
I prefer Linux's software raid to most hardware raid - I've experienced several problems with hardware raid but not with software raid, and the talk about hardware raid being faster isn't backed up with statistics or facts.
I like Linux' software RAID too - I use RAID1 all over the place. The one thing hardware RAID (with battery backed cache) does is plug that one little hole that software RAID cannot. I can't quite remember what it is, but AFAIR, in case of a power loss, there is a small risk of screwing up a software RAID5 array. The reason I'm looking at the hardware RAID using this array is simply cost and ease-of-use - these 2nd hand Compaq Storageworks arrays are almost being given away and they're hot-plug everything. Get one of these, and perhaps a 2nd one for spareparts and you're set storagewise for quite some time.
With 24 disks you could go with a fairly complicated but almost unbelievably robust setup, and in fact with 24 disks if you can afford the space you can mix some mirroring up in there.
I feel fairly certain mirroring will be part of it, yes. Space isn't too important - if I can make 1Tb out of it and still be able to survive a two-drive failure, I'll be quite happy. /Per Jessen, Zürich