Preinstalling SQL Express 2008 R2 for Lync Server 2010 RTCLOCAL instance

With the central management store and topology concepts introduced with Lync Server 2010, any instance of Lync Server 2010 will run Local Configuration Store that is hosted by an installation of SQL Express 2008 named instance called RTCLOCAL. The topology database is called XDS.

On servers runing as Front End server, the role of the SQL Express 2008 RTCLOCAL instance is more than just as a Local Configuration Store as it is hosting the local registrar databases (RTC and RTCDYN).

In a large pool, the local registrar databases can grow beyond the 4GB database size limit imposed by SQL Express 2008, therefore upgrading the RTCLOCAL instance to SQL Express 2008 R2 is recommended to avoid potential operational issues with the increase of database size limit in SQL Express 2008 R2 to 10GB.

Whilst it is possible to upgrade the RTCLOCAL instance after finishing the Install Local Configuration Store deployment step, it is also possible to preinstall SQL Express 2008 R2 as a shortcut to avoid having to run a separate time consuming upgrade process.

So before stepping into the deployment process, SQL Express 2008 R2 can be preinstalled and bootstrapper.exe will recognize the preinstalled RTCLOCAL instance and skip the installation of SQL Express 2008.

 

The latest SQL Express 2008 R2 x64 version can be downloaded from: https://download.microsoft.com/download/D/1/8/D1869DEC-2638-4854-81B7-0F37455F35EA/SQLEXPR_x64_ENU.exe

 

And the following one liner can be used to preinstall SQL Express 2008 R2 RTCLOCAL instance:

SQLEXPR_x64_ENU.EXE /IACCEPTSQLSERVERLICENSETERMS /ACTION=Install /FEATURES=SQLEngine,Tools /INSTANCENAME=RTCLOCAL /TCPENABLED=1 /SQLSVCACCOUNT="NT AUTHORITY\NetworkService" /SQLSYSADMINACCOUNTS="Builtin\Administrators" /BROWSERSVCSTARTUPTYPE="Automatic" /AGTSVCACCOUNT="NT AUTHORITY\NetworkService" /SQLSVCSTARTUPTYPE="Automatic" /INDICATEPROGRESS /Q

 

Note: for a Lync Server 2010 Standard Edition installation, the main backend database instance (RTC) is also hosted by SQL Express 2008, and can be preinstalled using SQL Express 2008 R2 as well by changing the instance name from the one liner above to /INSTANCENAME=RTC

 

Although the maximum database size increase is only beneficial to Front End servers, when deploying new Lync Server 2010 servers today, regardless the server roles, standardising the RTCLOCAL instance to SQL Express 2008 R2 will ensure that all Lync servers are running the latest supported SQL Express version.

 

- Agus Rachman, Senior Consultant, Microsoft Services (with special thanks to Ales Moskon, Senior Consultant, Microsoft Services for the collaboration as SQL SME).