Now that you have a picture outlining how Exchange Server 2007 stores and storage groups work, it’s a good time to discuss some best practices to consider when you design the physical storage infrastructure that supports your Exchange Server 2007 environment.
First, before you get into designing your storage architecture, you should understand what storage technologies are supported by Exchange Server 2007. The supported storage technologies are
Direct-attached Serial ATA (SATA) or Serial Attached SCSI (SAS) disks.
iSCSI. This is the only network-based storage supported by Exchange Server 2007. Exchange Server 2007 no longer supports Network Attached Storage (NAS).