"It's about time," says storage consultant Marc Farley of Microsoft's announcement this week about NAS support for Exchange Server 2003 email server, a sentiment undoubtedly echoed by many storage managers. Even Marcus Schmidt, Microsoft's senior product manager for Windows Storage Server, readily admits that customers and NAS OEMs have been asking for that capability for two years.
Now that Microsoft has produced a solution, storage managers find themselves in the odd spot of having Microsoft evangelizing for NAS and chief competitor Network Appliance telling them that SANs are the way to go for Exchange.
For more than two years, users have been unable to use current versions of Exchange with NAS. Changes Microsoft made to the program after version 5.5 to enhance performance also had the unintended consequence of rendering it unusable with NAS. Last month, Microsoft released an update to Exchange that fixed part of the problem: Exchange's need to write directly to local or SAN storage, bypassing the file system.
That fix only applies to the message database and log files, however. A number of smaller administrative files need to be stored on the Exchange server or on the SAN.
This week's announcement fixed the other major problem: Exchange needs to find where its database and logs are stored as it boots, not after. The feature pack for Storage Server 2003 (SS03) includes code that runs on Exchange 2003 servers that provides a persistent connection to SS03 filers. It requires, however, that users implement Microsoft's Distributed File System (DFS) for the connection between Exchange and SS03.
While NAS support is already available in Exchange, the feature pack for SS03 will probably not be available for 60-90 days from the vendors who offer those products (such as Dell and HP).
Meanwhile, Network Appliance, the main alternative to SS03 and the vendor whose filers were commonly used for Exchange storage prior to Exchange 2000, says that it has no plans to leverage the new capabilities. Rod Mathews, senior director of marketing, says NetApp has moved to either Fibre Channel or native iSCSI block storage for Exchange.
He contends that SS03 still can't be clustered, an increasingly common requirement for large Exchange installations (some SS03 OEMs do add that capability). As well, he says Microsoft's two years of preaching that block is the only way to go for NAS have convinced many people to go the block route, particularly in large enterprises.
"Our large customers don't want a NAS solution for Exchange," says Mathews. He sees the Microsoft NAS approach as viable for "a few hundred" mailboxes. Microsoft's Schmidt says 1,500 is about the cutoff point for moving to a SAN.
What about smaller companies who can't afford Fibre Channel SANs and aren't ready to bite on iSCSI yet, but want the benefits of networked storage through NAS?
"They'll have to buy Storage Server 2003 through one of Microsoft's OEMs," says Mathews.