Microsoft distributes Microsoft SQL Server 2008 or Microsoft SQL Server 2008 R2 fixes as one downloadable file. Because the fixes are cumulative, each new release contains all the hotfixes and all the security fixes that were included with the previous SQL Server 2008 or SQL Server 2008 R2 fix release.
Symptoms
After you enable change tracking in a Microsoft SQL Server 2008, in a Microsoft SQL Server 2008 R2, in a Microsoft SQL Server 2012, or in a SQL Server 2014 database, backup operations fail, and an error message that resembles the following is logged in the SQL Server error log file:
<Date><Time> <spid> Error: 2601, Severity: 14, State: 1.
<Date><Time> <spid> Cannot insert duplicate key row in object 'sys.syscommittab' with unique index '<Index Name>'. <Date><Time> <spid> Error: 3999, Severity: 17, State: 1. <Date><Time> <spid> Failed to flush the commit table to disk in dbid <Database ID> due to error 2601. Check the errorlog for more information.Additionally, you receive a 2601 error code when SQL Server 2008 tries to perform a checkpoint operation on the database.
Note For an overview of SQL Server database checkpoints, go to the following MSDN website:Resolution
Service pack information for SQL Server 2008 R2
To resolve this problem, obtain the latest service pack for SQL Server 2008 R2. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
2527041How to obtain the latest service pack for SQL Server 2008 R2
Cumulative update information
The issue was first fixed in the following cumulative update of SQL Server:
Each new cumulative update for SQL Server contains all the hotfixes and all the security fixes that were included with the previous cumulative update. We recommend that you download and install the latest cumulative updates for SQL Server:
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
References
For more information about the Incremental Servicing Model for SQL Server, click the following article number to view the article in the Microsoft Knowledge Base:
935897 An Incremental Servicing Model is available from the SQL Server team to deliver hotfixes for reported problemsFor more information about the naming schema for SQL Server updates, click the following article number to view the article in the Microsoft Knowledge Base:
822499 Naming schema for Microsoft SQL Server software update packagesFor more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
More Information
To fix a related issue in SQL Server, see the following KB article:Duplicate key rows from the sys.syscommittab table in SQL Server