Currently I'm setting up a Lync environment based on a standard edition. I've already installed Lync Server which is running fine. Next I'm planning to install a persistent chat instance collocated on my standard edition front-end. After reading a couple of persistent chat deployment guides, I'm still having questions. So far I understand it's possible to collocate a persistent chat instance on the standard edition front-end server. A standard edition front-end is using a local SQL Express instance "RTC" to store the persistent user data. Do I need to create a new SQL Express instance on my Standard Edition server or do I need to select current RTC instance? Is the Lync deployment wizard able to create an extra SQL Express instance (e.g. Chat) when configured in the topology builder?
You do not need to create a new SQL Express instance when collocated with Lync Standard Edition. Persistent Chat will use the same RTC instance and create a new database named "mgc".
Publishing Topology from the Topology Builder will connect to the instance and create the database.