Migrating to Exchange 2010: Fundamental decisions

Even in organizations that aren't considering any moves away from Microsoft, there are important decisions to be made before migrating to Exchange 2010. John Joyner presents four possible paths, including on-premise and cloud solutions.

Organizations running previous versions of Microsoft's email and group collaboration flagship, such as Exchange Server 2003 or Exchange Server 2007, know they are missing the boat in some way. The current release, Exchange Server 2010, has some distinct architecture and feature benefits that business users are eager to enjoy. However, for many reasons, organizations may be deterred from beginning a migration to Exchange 2010.

Making some basic decisions on the right direction for messaging services in your organization is the first step, and this includes deciding whether to migrate some or all messaging services to the cloud. If you will keep Exchange 2010 on-premise, your decisions might include how many mailbox server(s) to deploy in order to leverage new disaster-tolerant features such as Database Availability Groups (DAGs).

On-premise or cloud?

Many organizations report that maintenance and upkeep of their messaging system is the most intensive aspect of their I.T. operations. Issues such as high availability, archiving, backup and restore, anti-spam, storage management and many other considerations compound to make email not only the most business critical service at many organizations, but also the most complex. Your first decision is whether you can rule out moving your messaging infrastructure to the cloud as a strategic business benefit. Cloud options from Microsoft include Exchange Online and Office 365.

Exchange Online

A basic package at $5 per user per month includes a 25-GB mailbox. An advanced package at $10 per user per month includes unlimited personal email archive storage, archiving/compliance services and connection to Exchange Unified Messaging voicemail. With Microsoft Office Outlook and your mobile devices properly setup to work with Exchange Online, your business users will experience no loss of performance compared to on-premise Exchange.

Office 365

Formerly labeled Business Productivity Suite Online (BPOS), Office 365 is a hosted suite of services that includes most of the features of Exchange Online basic plus Office Web Apps, Lync mobile communicator, and SharePoint for $6 per user per month. Enterprise versions of Office 365 that can integrate with on-premise Active Directory, or even PBX phone systems for the complete Unified Messaging experience, vary from $10 to $27 per user per month.

Investigate the features and the price-points of moving to online messaging for your organization. A rule of thumb can involve the degree of customization your current Exchange environment has. If you have a basic messaging infrastructure running many default settings, lean towards a cloud-based solution. Conversely, if you have complex archive, connectors, or compliance solutions in place, lean towards an on-premise migration that leverages existing investments. In either case, you can quantify the cost of staying on-premise, in the process validating your business needs for specific messaging services.

On-premise Exchange 2010 for the small business

Microsoft Small Business Server (SBS) 2011 Standard Edition includes a full featured copy of Exchange 2010 Standard Edition, properly configured "out of the box" for secure operation. SBS 2011 Standard includes valuable configuration of the Exchange Internet send and receive connectors and web publishing of Outlook Web and Active-Sync features. SBS 2011 Standard has a limited usage and license scenario, supporting under 75 users in a single domain.

If your organization is small enough and needs on-premise email for strategic reasons, SBS 2011 Standard can present a great value, about $2,500 retail for 25 users and mailboxes, all Windows Server and Exchange Server client access licenses included. This is a very cost effective way for small organizations to use Active-Sync devices like mobile smartphones with Exchange 2010.

Exchange 2010 on-premise for larger organizations

For all other organizations, a migration to Exchange 2010 represents a change in how server and storage resources are allocated to support messaging. Exchange 2010 introduces the concept of Database Availability Groups (DAGs) as a "unit" of production database and log storage files -- that are replicated constantly to one or more passive copies.

  • Running one local passive DAG copy protects against local storage failures.
  • Running additional (remote) passive DAG copies provides geographic fault tolerance.

So a key decision involves the number and location of passive DAGs; this information drives storage and backup requirements for your business.

A great advance of Exchange 2010 DAGs over the storage mechanisms used in Exchange 2003 and Exchange 2007 is that complex cluster and Storage Area Network (SAN) support is no longer mandatory to achieve high availability of Exchange services. In fact, Exchange 2010 does not require Storage Area Network (SAN) shared storage for any high availability feature. This lets you use less expensive hardware to host Exchange 2010 without a loss of performance or safety.

Learn about new Exchange 2010 Personal Archive and search features for cross-mailbox search, which provides users with online archive mailboxes and helps eliminate ".PST" files. A combination of what your DAG strategy is, and to what extent you might employ personal archives, will drive the overall mailbox server and storage requirements of your Exchange 2010 deployment.