Everyone,

I have just gotten my hands on a server with 24 disks configured in 3 RAID-5 arrays of 8x8x7 disks with one hot spare.

I want to split the partitions into two: main and backup.

I was thinking of using LVM2 to do this since it allows arbitrary filesystem sizes and can split each filesystem across multiple disks. However, this has implications for robustness since the whole LVM volume goes down if one of the arrays fail.

So should I do the three partition split and work out some other way of splitting them up or would LVM be ok?

Thanks.

Actually, each raid array appears as one large disk. Don't think you can partition one of those?
Easiest way is to reconfigure the disks as 2 x 12 (2 raids x 12 disks each).
With that many disks per array, I'd look at RAID 6 or even 10 : http://en.wikipedia.org/wiki/RAID#Standard_levels