Microsoft exchange server 2007, currently in beta and slated to ship later this year or in early 2007, includes...
several new features that will have a profound effect on the kind of storage you'll need and how to protect it.
Chief among those changes is that Exchange's inner workings have been retooled to operate in a 64-bit environment, resulting in better I/O performance. "We've been able to reduce the I/O requirements to the storage by roughly 70%," says Ray Mohrman, Microsoft's technical product manager, Exchange Server. Other changes that could impact storage are expanded mailbox sizes and improved support for unified messaging, which could add voice mail and faxes to users' in-boxes.
"Microsoft is getting a large amount of scalability out of improvements to the overall architecture and the scalability of the database by this 64-bit update to the database," says Lee Benjamin, analyst for San Francisco-based Ferris Research. If the I/O load is reduced, it may be possible to use higher capacity, lower performing disks in Exchange instead of the high-end disks preferred today.
Exchange Server 2007 also includes two forms of continuous replication--Clustered Continuous Replication and Local Continuous Replication--that let you asynchronously replicate the production Exchange database. "We're enabling a hot standby of the database so that in the case of a failover, you can quickly just repoint Exchange to this second set of storage," says Mohrman.
Replication requires additional disk capacity equivalent to the production database--and its anticipated growth--to house the replica database, but the flipside is that the replica can be used to ease Exchange backup. "I can back up the replica and not impact the mailbox server," notes Benjamin. Being able to back up the mail system without affecting production is "one of the biggest advantages of leveraging this [replication] capability," says Keith McCall, CTO at Azaleos, a vendor of turnkey Exchange systems and management services.
New compliance features can move or delete messages from mailboxes based on policies defined by an admin. This functionality may be somewhat basic vs. dedicated archiving apps; however, it may suffice for some organizations, while others may use it in conjunction with an archiving app. "Microsoft's going to leave the archiving world to the third parties," says Ferris Research's Benjamin. He sees the new compliance features as more of an aid than a replacement of archiving apps. "They're putting in better plumbing for archiving," he says.
But policy-based message management tools can be used to stem Exchange storage growth. "We see it as a rule set that administrators can set up to help with retention and managing users' in-boxes," says Microsoft's Mohrman. Perhaps most significantly, the retention policies could limit or even eliminate the need for .PST files, which tend to bloat Exchange's storage requirements.
One remaining issue is the need to take the Exchange database offline to reclaim space freed by archiving older messages. Although some people anticipated a change in this process with Exchange Server 2007, online compaction and defragmentation aren't in this release.
The unified messaging enhancements make it easier to integrate Exchange with VoIP and digital PBX systems, but the additional message flow from data like voice mail shouldn't significantly affect the overall Exchange message store, says Mohrman.
Azaleos' McCall concurs. "I personally don't think there's going to be a huge amount of storage impact," he says. With voice mail, "you're talking about maybe 60KB or 100KB per message," he notes, while Word or PowerPoint attachments are frequently several megabytes in size.