We've had an interesting VSS-related problem when attempting to take TimeFinder/Snap backups of a SQL Server database concurrently with a TSM file system backup. However I suspect this could potentially affect anyone using a combination of hardware and software providers in VSS.
In our scenario we had a clustered SQL Server instance with user databases on a LUN from an EMC Symmetrix (P:). We were also using VSS as the snapshot provider on the TSM file system backups of the local disk (C:). The problem we encountered was that the periodic snaps that we took of the databases on P: using Replication Manager would fail whenever there was a file system backup of the C: drive being performed via the TSM B/A Client. When it failed the following messages were logged by RM: 24-Jun-2009 15:09:41 xxxxxxxxxx 100711 INFORMATION: The SQL BACKUP command completed. Details [Microsoft][ODBC SQL Server Driver][SQL Server]Processed 0 pages for database 'XXX'. 24-Jun-2009 15:09:41 xxxxxxxxxx 100711 INFORMATION: The SQL BACKUP command completed. Details [Microsoft][ODBC SQL Server Driver][SQL Server]BACKUP DATABASE successfully processed 0 pages in 10.161 seconds (0.000 MB/sec).. 24-Jun-2009 15:09:41 xxxxxxxxxx 000711 ERROR: Microsoft Volume Shadow Copy error: The I/O writes cannot be held during the shadow copy creation period. Please verify the load and configuration of storage array and try again. 24-Jun-2009 15:09:41 xxxxxxxxxx 026202 ERROR: Storage Services operation waitVSSCompletion failed with an error as follows: Wait Snapshot completion failed. 24-Jun-2009 15:09:41 xxxxxxxxxx 026084 ERROR: Storage Services operation processExecute failed with an error as follows: Storage Services has terminated with an error. With the help of some excellent analysis from an EMC support representative, my colleague was eventually able to determine that the problem was due to the location of the shadow copies of the C: drive. Using the VSSADMIN LIST SHADOWSTORAGE command during the TSM file system backup, it became apparent that, by default, the shadow copies of the C: drive were being stored on the P: drive.The choice of the P: drive for the shadow copies was consistent, but probably fairly arbitrary taking into account for example free space. However the presence of the shadow copy on P: appeared to be interfering with the EMC hardware provider's ability to snap the LUN within the array. The solution was simple - we confined the shadow copies of the local disks to local disks by defining shadow copy storage associations thus: VSSADMIN ADD SHADOWSTORAGE /FOR=C: /ON=D: Regards Neil Schofield Yorkshire Water ----------------------------------------- Ever wondered how your water works? - now you can see for yourself with a tour of our water or waste water treatment works across Yorkshire - click here http://www.yorkshirewater.com/see-how-your-water-works.aspx to book now. The information in this e-mail is confidential and may also be legally privileged. The contents are intended for recipient only and are subject to the legal notice available at http://www.keldagroup.com/email.htm Yorkshire Water Services Limited Registered Office Western House Halifax Road Bradford BD6 2SZ Registered in England and Wales No 2366682
