Microsoft's storage recommendations vary depending on the Exchange server's expected workload. For a server that will be servicing a large number of users though, Microsoft recommends the following disk configuration:
|C:||Direct-attached storage (RAID 1)||Windows, Exchange, system files|
|D:||Direct-attached storage (RAID 1)||Pagefile|
|E:||SAN RAID 0+1||MTA and SMTP queues|
|F:||SAN RAID 1||Log files for first storage group|
|G:||SAN RAID 0+1||Databases for the first storage group|
If your Exchange server contains multiple storage groups, Microsoft recommends that you create extra volumes. For each Exchange Server storage group, the log files should be placed on a SAN-based RAID 1 array; the Exchange Server databases should be placed on a SAN-based RAID 0+1 array.
Volumes C: and D: are recommended to be on direct-attached RAID 1 volumes. RAID 1 refers to mirrored drives. The significance of this configuration is that the pagefile is kept separate from the system drive for performance reasons. Both the system drive and the drive containing the pagefile are mirrored for fault tolerance.
Microsoft then recommends using separate volumes for databases within an Exchange Server storage group, and the transaction logs associated with that storage group, for fault tolerance. That way, if there is a problem with the disks containing the databases, the transaction logs (which are necessary for a complete database restoration) are unaffected.
Microsoft also suggests dedicating a separate volume to the MTA and SMTP queues. This configuration prevents disk I/O related to SMTP mail flow from negatively impacting performance on the volumes used to store the Exchange Server databases and transaction logs.
In the above table, Microsoft recommends that the volumes used for the MTA and SMTP queues and database be SAN RAID 0+1 arrays. A RAID 0+1 array is basically a mirrored RAID 0 array.
While Microsoft recommends the use of RAID 1 and RAID 0+1, these are by no means the only RAID types that will work with Exchange Server. In fact, the aforementioned configuration is probably only optimal in a SAN-based deployment. You are probably better off using an alternate RAID configuration in a non-SAN storage scenario.
CRASH COURSE: EXCHANGE SERVER 2003 STORAGE MANAGEMENT
Part 1: Microsoft's Exchange Server storage recommendations
Part 2: RAID configuration options for Exchange Server storage
Part 3: Using a SAN for Exchange Server storage
Part 4: Using NAS for Exchange Server storage
Part 5: Using DAS for Exchange Server storage
Part 6: Related resources on Exchange Server storage management
|ABOUT THE AUTHOR:|
| Brien M. Posey, MCSE
Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Exchange Server, and has previously received Microsoft's MVP award for Windows Server and Internet Information Server (IIS). Brien has served as CIO for a nationwide chain of hospitals and was once responsible for the Department of Information Management at Fort Knox. As a freelance technical writer, Brien has written for Microsoft, TechTarget, CNET, ZDNet, MSD2D, Relevant Technologies and other technology companies. You can visit Brien's personal Web site at http://www.brienposey.com.