If you didn’t catch it, there is an important note in the KB Article attached to the Lync Server 2010 Knowledge Base article, KB2493736 regarding a SQL database update that must be performed in addition to the installation of the CU3 software patch. To install the SQL update, the KB article states the following under installation Method 1:
On Standard Edition Server and Enterprise Edition – Front end server once you have installed update for core components, the updated sql files will be dropped on the server. Then, run the following cmdlet to apply the changes:
- In a Lync Server 2010 Standard Edition environment, run the cmdlet from the Standard Edition server.
- In a Lync Server 2010 Enterprise Edition environment in which the archiving/monitoring services are collocated with an Enterprise Edition back-end server, run this cmdlet from the Enterprise Edition back-end server.
- In a Lync Server 2010 Enterprise Edition environment in which the archiving/monitoring services are not collocated with an Enterprise Edition back-end server , run this cmdlet from the Enterprise Edition front-end server.
If the RTCDyn databases are removed after you run the cmdlet without the UseDefaultSqlPaths parameter, run the following cmdlet to restore the RTCDyn databases:
Note The RtcDyn log is located under the path of the rtcdyn.ldf file. The RtcDyn data is located under the path of the rtcdyn.mdf file.
I installed the CU3 update patch on several Front End Pool servers in my lab and rebooted. I was a little confused since, following the reboot, Lync Services started and everything seemed to work OK. I wondered… was the SQL updated required? Would something eventually break? or did the ServerUpdateInstaller.exe run the SQL update automatically? To many questions…
Searching about the issue, the only thing I could find was a reference to a MS Forum post by a Microsoft CSG stating that the database updated was an “absolute requirement”. See Forum post Lync CU3 SQL update questions.
I was not entirely convinced and decided to dig in a little deeper. While comparing a couple Front End pools in varies different states, my colleague discovered that on servers that had been fully patched with CU3 AND had the SQL database update applied, there was an important difference in the back-end pool RTC database. The dbo.DbConfigInt table contained an extra row as shown below:
Before applying the SQL update, the DbVersionUpgrade row does not exist and the table only contains 13 rows. After applying the SQL database upgrade as described in the KB Article, the table has 14 rows and shows DbVersionUpgrade with a value of 1. Also important to note that this is only reflected in the Pool Back-end Database and not in the RTCLOCAL replica.
I have been unable to determine if there are any negative repercussions if the SQL database update is not installed and I have seen several servers running just fine with CU3 installed without the SQL database update. I can also report that installing CU3 via Microsoft Update does not install the database update as servers patched in this manner do not show the DbVersionUpgrade row in the database.
I would encourage anyone applying CU3 to Lync Servers to run the database update as shown in the KB article. You can check to see if the SQL database update was applied by checking for DbVersionUpgrade with a value of 1 in the dbo.DbConfigInt table of the Pool Back-end Database.
If anyone knows of any negative side effects to not running the SQL database update, please share via the comments!
Credit goes to Paul Placanio @ Ronco Communications for finding the new DbVersionUpgrade row in the dbo.DbConfigInt table on servers with the SQL database update applied.
See Lync Server 2010 Database Updates Explained – Part 2 for more information.