Those eyeing a migration to Exchange 2010 will find lots of options that improve the platform, but they won't come without careful attention to deployment details including the rollout of Windows Server 2008, says one expert.

Exchange 2010, which was released to manufacturing recently, includes new storage and deployment options, enhanced inbox management capabilities, built in email archiving, new database clustering, and additional hardware options. And while it all is designed to add up to a better Exchange, it doesn't eliminate the complexity of deploying the messaging server, says Lee Dumas, the director of architecture for Azaleos, a provider of remote management services for Exchange and SharePoint.

To get all that, the effort begins before Exchange is even out of the box given that the software requires Windows Server 2008.

"There are a lot of things that make up what is Windows 2008, so it will be important to have a good plan to roll that out," says Dumas, one of less than 100 Microsoft Certified Architects and a former member of Microsoft's Exchange development team. "It is important to have a good server image before you go out and start building your messaging server on top of that."

And Exchange brings its own set of challenges. "I'm not slamming Exchange, but to achieve the level of SLAs, and dealing with large amounts of data, multiple copies of databases, server roles, and load balancing makes complexity inherent in getting the whole system in place," he said.

The rewards, however, will follow for those that heed due diligence, he says.

One of the marquee features for IT is the new Database Availability Groups (DAG). "It's a cleaner strategy for clustering locally and for disaster recovery. You can go deeper with more copies of the database itself and you're not limited to two copies like you were with CCR [cluster continuous replication] technology," he says. In addition, users won't need to use additional features to take database replications off site.

Dumas says another important improvement is support for up to 16 databases in a DAG. "What that does is allows administrators to have local copies in the same data centre, as well as a second or even third data centre that has up to date copies of Exchange," he said.

Microsoft also has tweaked replication to make loads more evenly distributed using a new feature called MAPI on the Middle Tier (MOMT), which cuts failover times dramatically, including sub 60 second response time.

"Previously users could only achieve these kinds of failover times with third party technology," Dumas says.

Dumas says another change users will notice is that they can use less expensive hardware across the board. On the front end, Microsoft says Exchange's front end servers can be scaled out using multiple inexpensive servers rather than using fewer larger servers.

"Microsoft has put out recommendations about using hardware load balancing in front of the front end servers, which is kind of an interesting recommendation but a good one to hear," Dumas says.

On the back end, he says, some less expensive hardware can be used, based on how Exchange 2010 roles are deployed.

Dumas also noted that users who moved to 64 bit servers with migrations to Exchange 2007 can reuse that hardware. Those moving from 32 bit Exchange 2003 to the 2010 version, however, will have to purchase new servers.

On the virtualisation front, users that do choose servers with large numbers of cores and lots of horsepower can virtualise Exchange tasks while taking advantage of its failover capabilities as well.

And Dumas says there are features for end users that could influence deployment decisions, most notably the redesigned Outlook Web Access (OWA).

"With the online push, OWA needs to be very functional," Dumas says. "This time around Microsoft has done a good job making OWA something that can replace the Outlook client."

He says OWA 2010 gives companies looking to cut costs an alternative to licencing Office 2010 or Outlook 2010.

Early adopters such as Ford are already planning on tapping the new OWA client for its mobile workforce. OWA 2010 has a number of new features including expanded browser support, drag and drop, spell checking, notifications, conversation views, and new display features.

Dumas says Exchange 2010 adopters will have to pay careful attention to archiving and mailbox size given the fact mailboxes now can be multiple gigabytes.

"Having a 5GB or 10GB mailbox is now a reality in Exchange 2010," he says.

And those deploying the server need to understand this is not just another upgrade to Exchange.

"For all intents and purposes this is a new product, they have rewritten large parts of the product," Dumas says. What hasn't changed, he says, is the overall product complexity. 

"There are still a lot of moving parts," he says. "There is going to be large amounts of data. How do you back that up, keep that data from corrupting, and how do you replicate all those things will become more difficult as people put more and more data into their inbox."

Dumas says there are other gotchas to look out for in deployment planning.

"MAPI on the Middle Tier and load balancing for the front end servers are going to create network challenges," he says. "Hardware load balancers are not cheap so that is something to consider in a budgeting cycle."

In addition, MOMT is part of the new Client Access Service (CAS) in E2010, which handles connectivity for all major endpoint technologies in Exchange including Outlook, Outlook Web Access and ActiveSync. Some have pointed to CAS as a single point of failure.

Other deployment considerations center on the need for Exchange 2007 SP2 in order to run mixed 2007/ 2010 environments, and that users won't be able to do in place upgrades from 2007 to 2010.

In addition, new management tools like remote PowerShell and role based access control will challenge administrators and end users. New monitoring tools will "create learning curves for administrators that they should pay attention to," Dumas says.

On the bright side, while users can deploy cheap storage, they don't have to throw away existing storage investments and replace it with cheap attached storage.

"I think what they are saying is that you don't have to go out and buy Fibre Channel disks anymore," he says. "But you need a focus around storage and data management."