We have a SQL 2K database with an EMC Clariion FC4500 (SAN) as the disk subsystem. We are in the process of adding more drives. A couple of questions have poped up among our DB team relating to how to properly configure the LUNs on each RAID group to achieve optimal performance for SQL 2k. Specifically, is there a rule of thumb that anyone knows of, or follows, that dictates the correct number of LUNs to create on each raid group? For example, we currently have 4 LUNS created on a 5+1 (36GB Drive RAID 5) each containing one database file. Questions are being raised whether this is correct, as a matter of fact there are entities withing the group that insist having more than one LUN per RAID group dramatically affects performance negatively. This runs counter to what I was instructed to do by EMC. I'm pretty neutral on the matter and only want to have the system configured optimally. I cannot find any documentation specifically addressing this, which is why I'm turning to you all. Any help, or direction, you can provide will bring great Karma. Thanks, Tony -Tony C.