Microsoft, reacting to a slew of questions from end-users, says timing issues and technical considerations kept it from supporting Exchange 2007 SP2 on the new Windows Server 2008 R2.
On the Exchange team blog, Nino Bilic, a member of the Exchange product quality team at Microsoft, wrote that there are two primary technical considerations for not supporting the messaging server on the new server OS.
Users have been peppering Microsoft with questions over the past few months and the vendor chose Monday to explain its decision as it prepares to put the final touches on Exchange 2010, which aligns with other new infrastructure, namely Windows Server 2008 R2, Windows 7 and Office 2010.
"Two primary technical points drove our decision to not support Windows Server 2008 R2," Bilic wrote. "First, Windows Server 2008 R2, while an incremental OS upgrade, creates significant testing requirements for Exchange 2007. Because the Exchange 2007 SP2 engineering preceded the Windows Server 2008 R2 RTM, Exchange 2007 SP2 would have had to be delayed significantly to align testing schedules."
Bilic said the second point involves not supporting the upgrade of a server OS underneath an existing Exchange server. "The primary need is to support Windows Server 2008 R2 domain controllers in an existing Exchange 2007 deployment, which we have done."
Exchange 2007 SP2 can work against those domain controllers because no part of the Exchange infrastructure is running on the domain controller.
What users are missing is the ability to run any Exchange 2007 R2 components on the new server, including administrative tools on Windows Server 2008 R2.
Bilic said the level of testing that would have been required to ensure only a "minimum level" of compatibility would have been significant and still denied users many of the features of the new server OS.
In addition, he said the work likely would have altered the delivery schedule for Exchange 2010.
Bilic said that fact drove Microsoft to conclude the best decision was to release Exchange 2010 as close as possible to Windows Server 2008 R2, which is now available. Exchange 2010 is expected to ship in November.
"We felt that thoroughly validating the combination of Exchange 2010 on Windows Server 2008 R2 allowed us to focus on delivering great solutions which would be fully tested and would support the features of Windows Server 2008 R2," Bilic wrote. "This is a hard trade-off to make, but we believe it is the right one and a good balance between serving existing customers and driving innovation."
The new Exchange 2010 server includes a number of new features, including high-availability and cross-domain integration using techniques such as pairing the server with Windows Server 2008 clustering technology and directory federation features. The server also includes new archiving features.
"We recognize that there are some downstream impacts to this decision related to administration-only installs," Bilic wrote. "The technical problem for us is that an administration install of Exchange is almost identical to a full Exchange server installation."
An administration install is when only the administrative interface, used to manage server properties and other features, is loaded on the server OS.
Lee Dumas, the director of architecture at managed Exchange service provider Azaleos and a former Microsoft employee on the Exchange team, noted that Exchange 2007 SP2 contains the schema updates that are part of Exchange 2010.
"So deploying SP2 prepares you for Exchange 2010. The earlier they can release SP2 the more customers will be prepared for 2010 so that might have had something to do with this as well," he said. Dumas noted that releasing planned schema updates with a previous version of Exchange is something new for Microsoft.
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This story, "Why Microsoft kept Exchange 2007 SP2 off latest Windows Server" was originally published by Network World.