SQL Mirror is a very common Back End Server configuration for Lync/Skype for Business Server deployments. Lync/Skype for Business Server uses SQL Mirroring option with or without witness server. Witness server configuration is mandatory if you want to achieve automatic failover. Normal SQL Server Instance or SQL Express edition can be used for witness configuration. Any SQL server can be used only once in Skype for Business Server. You can’t use same SQL server to configure two different mirror until or unless you don’t tweak the SQL configuration settings.
There is a challenge to change the configuration settings in an existing SQL mirror because Lync/Skype for Business Server configure the SQL Mirror and any change direct to the SQL configuration may arise unpredictable errors. Most of the errors or problems you can see while publishing the topology.
In this post, I’ll explain “how to change the witness server in SQL mirror configuration”; which is used by Lync/Skype for Business Server.
For SQL Server Mirror Configuration and required protocols and ports requirement, see SQL Configuration for Skype for Business Server
First of all open Topology Builder and download topology from existing deployment.
Go to the properties of the pool for which you want to change the configuration and go to the Association under General.
Uncheck the witness server option and publish the topology.
Once, topology is published successfully go to the shared components and delete the witness store which you have removed in previous step.
Publish the topology once again.
Once the topology has been publish successfully. Go to the Primary SQL server and select each Skype for Business database one by one and go to the properties.
Select mirroring from left panel and clear the witness configuration and click on OK.
Do the same steps for all the databases.
Once done go back to the topology and define new witness server and publish the topology.
Now, you are done J