raid 51?

[bissa]

I tried searching this, but it cut the 51 from the search.
has anyone ever seen a raid 51 setup before? if so what was store on it and why did thye need that much redundancy?

[lowfat]

Seems like a silly idea. Would make much more sense to have 2 separate RAID5 arrays on two different machines.

[grinder]

i have not seen one but it would be expensive to setup. Technically i think you are asking about a raid 5+0 setup... not a RAID 51.

a raid 51 would be two raid5's +1 (mirrored). Like lowfat says that makes little sense. That is two times your level of "hard drive failure" redundancy when you only need one. Typically you should have one layer of hard drive redundancy, coupled with a offline backup system (NAS, TAPE or over the internet style automated backup system).

Raid 5+0 (or raid 50) would be two RAID 5 array's striped for added performance. This would also be called a nested array. It would require a minimum of 6 hard drives to accomplish and because it's RAID 5 you would want a 8 port dedicated RAID 5 controller to pull it off properly. This would equate into an investment of over 1000 dollars into your storage system alone.

Do you have a specific application that would warrant the use of a RAID 50? I am just speculating, but i would imagine a single raid 10 would out-perform a RAID 50 setup.