[Beowulf] Surviving a double disk failure

[John Hearns]

2009/4/10 David Mathog <mathog at caltech.edu>:
>
>
> Thankfully I don't have to do this myself, not having data anywhere near
> that size to cope with, but it seems to me that backing up a nearly full
> 16TB RAID is likely to be a painful, expensive, exercise.
>
>
>
> Is there an easier/faster/cheaper way to do all of this?
>
Well, if you are handling quantities of data like that look at an HSM,
such as SGIs Data Migration Facility, in combination with an HSM-aware
backup package.

Seldom-accessed data is pushed off onto a cheaper, slower storage tier
such as tape or slower disk - you could even hav a virtual tape
library which uses disk packs.
Back up the main RAID with the backup package.

For added resiliency you can mirror the RAID to another unit in
another location, and should disaster occur you can switch to that
one.