News

Microsoft Releases Exchange 2013 Cumulative Update 1

• By Kurt Mackie
• April 02, 2013

Cumulative Update 1 (CU1) for Exchange 2013 is now available from Microsoft, enabling organizations to go forward with on-premises deployments that mix Exchange Server 2013 with earlier Exchange Server versions.

CU1 also adds hotfixes dating back to the release of Exchange 2013, along with some new features.

With the new CU1 in place, Exchange 2013 can coexist with Exchange 2010 Service Pack 3 or Exchange 2007 Service Pack 3 with Update Rollup 10. It also allows Exchange 2013 to work with a mix of those two legacy servers. Organizations trying to get Exchange 2013 working with Exchange 2003 are out of luck as it's not supported at all by Microsoft. A table showing the possible coexistence scenarios can be found here.

CU1 reflects Microsoft's new quarterly release cadence that it announced in February. IT pros now get full builds of products with these cumulative update releases, so they are going to be a bit fatter. This release, called "build 15.00.0620.029," is a 1.3 GB download and can be accessed here.

Install Caveats
This first cumulative update for Exchange 2013 comes with lots of caveats before installing it, which are outlined in an Exchange team announcement and the release notes. Organizations that just have an Exchange 2007 environment, but want to add Exchange 2010 at a later time, need to preserve at least one legacy server role if installing Exchange 2013 CU1.

"Once you remove the last server role of a legacy version, you will no longer be able to reintroduce that version into the environment," the Exchange team warned, in the announcement.

The CU1 release comes with schema changes. Active Directory first needs to be updated to account for the schema changes, as well as role-based access control updates and domain permission changes.

The cumulative update will create a new default offline address book (OAB). Clients will look for this new default OAB automatically, which can cause the clients to start full OAB downloads. IT pros can avoid that potential bandwidth hit by changing mailbox database settings to point to the current OAB before installing Exchange 2013, according to Microsoft's announcement.

CU1 comes with a big note about the Exchange 2013 architecture. Exchange 2013 is different from earlier releases in that it's architected with just two server roles, a mailbox role and client role. There's a restriction on uninstalling them if they are both installed on a single machine. Users have to remove both of them at the same time in that case; it's not possible to uninstall them individually, Microsoft warned.

Microsoft also offers a note that IT pros could be tripped up by mailbox size quotas. CU1 for Exchange 2013 will increase the size reporting of mailboxes by about 30 percent to 40 percent. Consequently, the Exchange team suggests that mailbox quotas may need to be increased before performing the update. Supposedly, the increased size isn't actually consumed. It just gets reported as larger.

"Again, this does not mean there will be an increase in the size of the database file on disk; only the attribution of space to each mailbox will increase," Microsoft's announcement explained.

New Functionality
CU1 also includes some new functionality, which seems to reflect Microsoft's new release strategy. Typically, cumulative updates have been described as just including product fixes, not new features, per Microsoft's standard terminology.

In this case, Microsoft added an address book policy routing agent in CU1. The management functionality was changed back to allowing groups to own other groups, so IT pros no longer need to run a script to make that happen. Public folders can now be accessed through the Outlook Web App.

There are lots of high-availability improvements included in CU1. An outline of those improvements can be found in this Microsoft blog post.

Microsoft's announcement also indicated that CU1 for Exchange 2013 will support a management pack for System Center Operations Manager, which will be available at a later date. No clue was provided as to when that might occur. Specifically, management packs for System Center Operations Manager 2007 R2 and System Center Operations Manager 2012 are in the works, according to the announcement.

Cancelling the update in process will stall the Exchange transport service, according to Microsoft Exchange MCM and MVP Jeff Guillet. He suggested in a blog post that IT pros remember to restart the Exchange transport service in such cases.