In Microsoft Lync Server 2010 you can configure your Central Management Server (CMS) on either an Enterprise Edition (EE) pool or on a Standard Edition (SE) pool. So where are the CMS master database and the replica databases located in those two scenarios?

In the EE pool case the master CMS database (called xds) is located in the regular SQL Server BE database instance, which per default is called rtc. All Lync servers will have a local replica of the CMS database and so will the FE’s in the EE pool hosting CMS. The FE’s will each have a SQL Express instance called rtclocal and the CMS replica will be stored in the xds database within that instance. This is shown in the picture below:

EE CMS

In the SE pool case the master CMS database is located in the regular SQL Express database used by the SE, which per default is called rtc. As noted above all Lync servers will have a local replica of the CMS database and so will the SE hosting CMS. The SE will have a SQL Express instance called rtclocal and the CMS replica will be stored in the xds database within that instance. This is shown in the picture below:

SE CMS