I need some assistance on properly configuring the hard disk subsystem for an Exhange 2007 deployment. We will initially have 350 user mailboxes. The server is a 2 x Quad Core with 12GB of Ram and 8 Hard Drive Bays. We do not have a SAN, so I am using SAS Hard Drives. The problem I am running into is how to seperate the hard disks and what RAID sets to use for each one. I did the Exchange 2007 Storage Calculator, and it suggests I have 5 LUNs. (Question 1) I know whata LUNis for a SAN, but if I don't have a SAN, should I translate this as a RAID set, thus having 5 RAID sets? The calcutor says I should have 2 database LUNs, 2 Transaction Log LUNs and 1 restore LUN. (Question 2) Is it more important to have the each storage group transaction log be on seperate RAID setsOR for each storage group to be on a seperate RAID set (1 database per storage group) I have a Hard Disk configuration in mind, but the configuration depends on the two questions above. Thanks in advance for your help. John Dombrowski