From what I saw (which may have changed) currently Cartman (that's the DB server right?) has two RAID 1 logical drives. RAID 1 is no faster for writes than a component HD. If write is where the performance hit is, the the logical drives should likely be setup as RAID 3.
I guess I will keep this short in case this was discussed somewhere and I missed it. Well and changing the RAID level after the fact is a pain in the rump.