SQL Server Error During Lync Install

I recently visited a client who was having a miserable time getting the Lync Central Management Store database created during the Topology publishing process. They kept seeing errors similar to below:

Error: Script failed (code “ERROR_CREATE_DB”) when installing “CentralMgmtStore” on “lyncserver.company.com”. For details, see the following log file: “C:UsersadminacctAppDataLocalTempCreate-CentralMgmtStore-lyncserver.company.com-[2011_01_03][10_32_38].log” 1/3/2011 10:32:38 AM Error

Error: An error occurred: “Microsoft.Rtc.Common.Data.SqlConnectionException” “Cannot open database “xds” requested by the login. The login failed.

Login failed for user ‘DOMAINadminacct’.”

There are LOTS of similar errors out there that people have encountered, unfortunately none applied to me. But I thought I’d put this handy little checklist together for anyone else who runs into this:

1. Checked to make sure the account had correct permission on the SQL server (technet)
2. Made sure that port 1433 was reachable on the SQL server (kb article)
3. Tried removing and re-installing Lync components on the front end (Mike Stacy)
4. Didn’t see errors related to packets on the SQL server (Terrence Luk)
5. Made sure that SQL was the right version (OCSPedia)

As it turned out, it was none of the above. But it was a good exercise going through and double-checking everything. My issue was more obscure: the default size of the model DB in SQL was set to 25 MB. Which seemed reasonable enough to me. However, the Lync DB Create process tries to create the CMS database with a size of 8 MB. And if the default size in the model DB is greater than 8 MB… you lose!
I found this kb article and followed the instructions to shrink the model DB size down to 2MB. It worked & saved the day.