Exchange Server 2007 Migration: Look Before You Leap

While Microsoft Exchange Server 2007 offers a range of benefits over previous versions, many organizations are intimidated by the complexities of setting up and managing the new platform. Armed with a little knowledge of the added capabilities—and a lot of planning and design preparation—enterprises can dramatically reduce the headaches associated with configuring, integrating and managing an Exchange Server 2007 environment.

Organizations considering a move to Exchange Server 2007 are probably aware of its numerous improvements to security, reliability and scalability. Those benefits, however, come with increased complexity. In fact, experts say some of the very things that make Exchange Server 2007 more reliable and easier to use also make it more difficult to set up and manage.

Rand Morimoto, president of Convergent Computing, cited PowerShell and Exchange Management Console as two new administrative tools that will ultimately simplify Exchange Server 2007 usage and management. But because those tools differ markedly from anything administrators might have used in the past, many IT teams are struggling to get used to them, Morimoto said.

Exchange Server 2007 also introduces a role-based setup architecture that offers installation flexibility, letting administrators make better use of hardware by targeting roles without draining system resources. Administrators can deploy the server roles individually on dedicated hardware or install multiple roles on the same physical server, with the roles administered as separate entities.

“With previous versions of Exchange, administrators were forced to install the entire Exchange product on a server, even though they only needed certain features,” said Jim Lucey, senior technical product manager of the Microsoft Exchange Server team. “With Exchange Server 2007, administrators can install on a role-by-role basis—for example, mailbox, client access, hub transport, edge transport and Unified Messaging. If administrators only need to deploy a hub transport server or a client access server, they can do so without the need to run additional roles. [But] because Unified Messaging is a new role with Exchange Server 2007, it has a higher learning curve for Exchange administrators.”

Another architectural change is that Exchange Server 2007 must be deployed on 64-bit hardware and will not support an in-place upgrade from any previous version of Exchange. Administrators must use the swing upgrade method to move an existing messaging service to Exchange Server 2007. According to Morimoto, many organizations have never worked with 64-bit Windows before, so they don’t know how to size, configure or optimize it properly.

Unlike prior versions of the software, in-place upgrades are not available with Exchange Server 2007, and companies with Exchange Server 2000 or 2003 will need to run both their legacy Exchange Server platform and Exchange Server 2007 in coexistence mode during the migration process. Exchange Server 5.5 users must first migrate to Exchange Server 2000/2003 before migrating to Exchange Server 2007.

Because Exchange Server 2007 only supports x64, many organizations require a server refresh. “Customers are concerned about data loss with continuous replication,” said Roger Frey, director of Microsoft solutions marketing at NetApp. “In the event of a primary-node failure, the passive node will come online and query the hub transport for missing mail. Should the entire site fail, that mail is lost.” Frey recommended host-based data replication products to replicate hub transport servers to a disaster recovery site, thereby ensuring near-zero data loss.

To address issues related to Exchange Server 2007’s learning curve, Lucey advises users to review Microsoft’s extensive planning documentation during the essential planning phase. “One of the most important things for any organization deploying a mission-critical application is to get the planning and architecture right from the start,” he said. “Like laying the foundation for a building, you want to make sure the design of your Exchange Server deployment is planned properly.”

Topics to consider in the planning phase, Lucey said, “include hardware, storage, site consolidation, server sizing, high-availability and disaster-recovery needs, Active Directory, security requirements, etc. Whether this is a small, medium or large Exchange organization, we have provided in-depth planning references for Exchange administrators to properly deploy Exchange Server 2007.”

Daniel Schneiderman, director of IT services at INFINIT Consulting, agreed that many of the problems administrators grapple with when setting up an Exchange Server 2007 environment can be avoided with due diligence. “Familiarize yourself with the new architecture and roles,” he advised. “Read the documentation for configuring an Exchange environment. Get familiar with where the new management tools are. Ultimately, the issues—certificate issues, security requirements, etc.—need to be planned for.”

Of course, not all of the challenges can be overcome by learning new tricks. E-mail migration across an enterprise can be one of the most daunting projects an IT organization undertakes. Administrators face disaster if intellectual-property or sales-contact information is lost during a migration. Chaos can result if employees are denied access to their inboxes for any length of time, as each lost hour translates to losses in productivity and sales.

NetApp’s Frey said the top pain points reported by his customers who have set up Exchange Server 2007 servers are large mailboxes, sizing and testing. “Microsoft is recommending larger mailboxes—2GB plus—which for most customers represent a ten- to twentyfold increase over existing mailbox sizes,” he said. “Managing and backing up such a large data set is difficult and, in the case of customers who run a streaming online backup, cannot be done in the common four-hour backup window.”

Sizing an Exchange Server 2007 environment has also become more complex, said Frey, because users can no longer measure and size user workloads in I/O operations per second (IOPS) and then use that number to size other servers. “With Exchange 2007, the user IOPS will change depending on the number of users in a storage group, the number of storage groups on a server and the amount of memory in the server,” he said.

Jason Fisher, Symantec’s director of product management for Backup Exec, warned that high availability and data recovery are points of particular concern for anyone setting up an Exchange environment. “As Exchange has evolved, Microsoft has stayed focused on being able to send and receive e-mail,” he said. “They’ve really kept that focus and created a best-in-breed product. But when it comes to high availability and recovery, it’s not their distinct competence. Anyone who relies on Exchange needs to invest in a data recovery product.”

According to Fisher, using a backup and recovery solution eliminates the need for daily backups while allowing quick recovery of individual mailboxes, messages and folders. Whether an organization runs Exchange Server 2007 in a standard deployment, a local continuous replication or a clustered continuous replication configuration, such a solution ensures that data is quickly recoverable and available.

Many companies today have massive databases, which can create user experience problems. For that reason, experts say it is essential to evaluate the current environment before migrating to Exchange Server 2007, since doing so can help an organization maintain compliance and minimize legal risk. One recommendation is to archive messaging data before migrating. In most cases, an Exchange Server 2007 migration involves a long project timeline and complex coexistence. Archiving helps reduce the timeline, c
onsolidate the infrastructure and protect mission-critical data.

Many migration issues could easily be avoided if administrators simply took the time to test—a necessary step for determining whether the environment will meet the customer requirements. Too many customers attempt to skip the testing phase, said NetApp’s Frey.

“With RAM being cheap,” said Convergent Computing’s Morimoto, “organizations usually put too much or too little memory in their Exchange servers. Exchange has optimum operating conditions based on the size of the organization, and too much or too little [memory] causes performance problems. Doing proper on-paper performance calculations, along with testing Exchange Server 2007 in a lab environment on the hardware that is anticipated to be used in production, allows an organization to properly test its assumptions.”

Beyond basic application compatibility, Exchange Server 2007 changes how organizations address disaster recovery, database recovery and systems management. “In the past, organizations used to snapshot databases using SAN storage technology, but Exchange 2007 has built-in database replication. That means an organization no longer needs SAN replication to protect Exchange,” said Morimoto. “But some organizations still try to configure Exchange 2007 to do SAN replication … they really get into a mess when they try to use old methods of data recovery in a new Exchange 2007 environment that has much better built-in tools. Likewise for tape backup: Since you now have a second copy of the database replicated in Exchange 2007, back up the secondary copy so you don’t impact the performance of the primary copy of the mail.”

C2C Systems CEO Dave Hunt said the storage limitations in Exchange Server 2007 make it necessary for companies to shift some of their data to a lower-cost device, but many fail to determine at the outset which data they will and will not move. “When you’re moving into a new house, you don’t just move all your old stuff to the attic and keep it there,” he said. “It’s the same thing with your data. If you’re migrating the data anyway, now is the time to implement a plan to manage it.”

Schneiderman also advises organizations that are not fully prepared for a complete setup or migration to take their time, since Exchange Server 2007 offers the flexibility to introduce server roles gradually and to support Exchange in a coexistence mode. The end-to-end process is designed to maintain messaging functionality and stability through the transition period.

“It’s not necessary to overcomplicate things,” Schneiderman said. “You can move to 2007 and keep your current environment; just introduce the 2007 server and move your mailboxes over.”

Most migrations cannot be done over a single weekend; many take several weeks or months. During that time, it is critical that messaging functionality be up and running without interruption, even when some user accounts are housed in Exchange Server 2007 and others remain in the source messaging platform. If administrators fail to establish coexistence between the messaging environments, users lose the ability to e-mail and schedule meetings with each other, share global address lists and view public folders.

To establish coexistence effectively, administrators must synchronize Active Directory and Exchange data—including directories, public folders and calendars—so that any changes made in one environment will be replicated in the other. By doing so, they can eliminate productivity losses due to interrupted workflow.

The upside to choosing a phased approach, said Schneiderman, is that if something goes wrong because of technical or human error, the organization will not have to roll back thousands of mailboxes at once.

When setting up and managing Exchange Server 2007, most organizations rely on third-party vendors to optimize Exchange Server performance. Hundreds of software and service solutions offer enhanced backup and restore, security and compliance, message archiving, and integration capabilities, which can make migration and management faster, easier and less expensive.

The caveat is that if administrators fail to use versions of those products that support Exchange Server 2007, or to get the guidance they need to migrate their software successfully, their headaches may mount during and after setup. Administrators thus should test the software’s functionality to ensure that it functions with the new platform and related software products.

Few would argue that delivering a current messaging system to employees is critical to maintaining a competitive advantage. Migrating to Exchange Server 2007 can be challenging, expensive, time-consuming and risky to business operations, but it doesn’t have to be. By taking the time to plan, design and test before starting the migration, administrators smoothly navigate the transition.

Published by: Systems Management News
Written by: Michelle Savage
Date Published: September 15, 2008

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