A month or so ago we started seeing crashes on the SQL Server associated with one of our dogfood TFS servers.  The crashes ultimately resulted in us having to restore the database from backup.  It was a significant work disturbance and an important thing to avoid.

We diagnosed the problem in tandem with the SQL Server team and discovered it was due to a SQL Server bug in tables using page compression.  That feature is only supported with SQL Server Enterprise Edition and above – but, that’s what we use.  TFS ships with SQL Server Standard Edition so the vast majority of customers won’t be affected.  You’ll only be affected if you separately obtained a SQL Server Enterprise or above license and installed it and pointed TFS at it.  Further, it only applies to you if you are using TFS 2010 or a preview of TFS 11.  We added support for SQL compression in TFS 2010 - before that (TFS 2008 & 2005, we didn't make use of the feature).

Fortunately, SQL has released a fix for the problem.

If you are using SQL Server 2008 Enterprise Edition or above with TFS, you need to update to SP1 CU6 (Apr 7, 2011) or SP2

If you are using SQL Server 2008 R2 Enterprise Edition or above with TFS, you need to update to either RTM CU7 (Jun 16, 2011) or SP1 CU1 (Aug 25, 2011)

You can read more about it in the KB article here: http://support.microsoft.com/kb/2668489.  You’ll also find links to the appropriate updates there.

I apologize for the inconvenience.

Brian