We are experiencing poor disk performance on our Exchange 2007 server (about 30 users) running on new Dell Poweredge 2900. It is installed on SBS 2008, with everything on one RAID 5, in separate volumes per Microsoft's Small Business Server setup guidelines. We have ordered 4 additional drives (15k RPM 147GB). What is the best way to configure the exchange data on the drives/volumes for optimal Exchange performance? Is it enough to have the logs and database on separate volumes on a RAID 1 or should we create two RAID sets?