XFS/LVM/Multipath on a single RAID volume

[Dave Hall]

Dave, Stan,

Not sure if you remember, but we corresponded for a while a couple years 
ago about some performance problems I was having with XFS on a 26TB 
SAS-attached RAID box.  If either of you is still working on XFS, I've 
got some new questions.  Actually, what I've got is a new array to set 
up.  Same size, but faster disks and a faster controller.  It will 
replace the existing array as the primary backup volume.

So since I have a fresh array that's not in production yet I was hoping 
to get some pointers on how to configure it to maximize XFS 
performance.  In particular, I've seen a suggestion that a multipathed 
array should be sliced up into logical drives and pasted back together 
with LVM.  Wondering also about putting the journal in a separate 
logical drive on the same array.

I am able to set up a 2-way multipath right now, and I might be able to 
justify adding a second controller to the array to get a 4-way multipath 
going.

Even if the LVM approach is the wrong one, I clearly have a rare chance 
to set this array up the right way.  Please let me know if you have any 
suggestions.

Thanks.

-Dave

Dave Hall
Binghamton University
kdhall at binghamton.edu
607-760-2328 (Cell)
607-777-4641 (Office)