Add Front End SQL Server Store
A Standard Edition server deployment automatically installs the required Microsoft SQL Server Express database software and SQL Server database. Therefore, all options are prepopulated, and you can't make changes to the default configuration.
The Front End pool of an Enterprise Edition server deployment requires a supported 64-bit edition of the SQL Server database software for the back-end database. You can either select a previously defined SQL Server database to be used for the back-end database, or define a new SQL Server database by specifying a fully qualified domain name (FQDN) of the server on which the SQL Server database is to reside, and the instance of SQL Server that you want to use for the new SQL Server database (which can be the default instance, or a named instance that you specify). You can also choose to enable mirroring on the SQL Server store, and specify a mirroring witness for automatic failover.
For details about SQL Server support, see Database Software and Clustering Support in the Supportability documentation. For details about setting up SQL Server for the back-end database, see Configure SQL Server for Lync Server 2010 in the Deployment documentation.
If the account that is used to publish the topology has the appropriate user rights and permissions, you can create the back-end database (real-time communications (RTC)) when you publish your topology. You can also create the database later, including as part of the installation procedure.
To install and deploy the databases on the SQL Server-based server for an Enterprise Edition deployment, you must be a member of the SQL Server sysadmins group for the SQL Server-based server where you are installing the database files. If you are not a member of the SQL Server sysadmins group, you must request to be added to the group until the database files are deployed. If you cannot be made a member of the sysadmins group, you should provide your SQL Server database administrator with the script to configure and deploy the databases. For details about the user rights and permissions that you need to accomplish the procedures, see Deployment Permissions for SQL Server.