[Beowulf] hardware RAID versus mdadm versus LVM-striping

[Rahul Nabar]

If I have a option between doing Hardware RAID versus having software
raid via mdadm is there a clear winner in terms of performance? Or is
the answer only resolvable by actual testing? I have a fairly fast
machine (Nehalem 2.26 GHz 8 cores) and 48 gigs of RAM.

Should I be using the vendor's hardware RAID or mdadm? In case a
generic answer is not possible, what might be a good way to test the
two options? Any other implications that I should be thinking about?

Finally, there;s always hybrid approaches. I could have several small
RAID5's  at the hardware level (RIAD5 seems ok since I have smaller
disks ~300 GB so not really in the domain where the RAID6 arguments
kick in, I think) Then using LVM I can integrate storage while asking
LVM to stripe across these RAID5's. Thus I'd get striping at two
levels: LVM (software) and RAID5 (hardware).

-- 
Rahul