Post reply

TDE Restore Problem - Intermittent - anyone else experienced this?

  • September 26, 2013 at 8:46 am

    #298294

    Hi All,

    We have a very strange problem restoring backups which has only started since TDE was implemented on 19th September 2013.

    This is on SQL Server 2008 (SP3) EE, running on Windows Server 2008 Enterprise (SP2) on a paired cluster.

    When TDE was initially implemented, test backups and restores were successfully completed without issue. Yesterday though, a backup was taken and proved to not restore (Msg 5243, Level 16, State 6, Line 1

    An inconsistency was detected during an internal operation. Please contact technical support.). We then attempted to restore scheduled backups from the previous 3 nights - same problem.

    Early this morning the instance was failed over to the other node. Test backups were taken and successfully restored. 5 backups between 05:30 and 11:45 proved to restore successfully. A further backup was taken at 13:30..... and the problems with restore re-started 😉 This leads us to believe that restarting SQL resolved the problem.... maybe memory related?

    There's nothing helpful in the event logs. There are stack dumps for each attempted restore.

    We've contacted MS, but in the interim I was wondering if anyone out there had experienced anything similar? We are suspecting TDE (as that is the only change made recently, and backups taken prior to TDE implementation still restore perfectly). It could of course be totally co-incidental and not related to TDE at all!

    Any help, ideas, thoughts etc would be gratefully received.

    Cheers

    Catherine

  • September 27, 2013 at 5:54 am

    #1653978

    Bump.....

  • December 19, 2013 at 8:41 am

    #1674861

    Hi All,

    I'm going to post the solution to the issue we experienced here - just in case in the future anyone else hit's the same problem.

    The database which we experienced the issue on had Torn Page Detection as it's Page Verification setting. Our backups are carried out with CHECKSUM. Once TDE was enabled, backups for this database completed but then could not be restored.

    The resolution was to remove TDE, amend Page Verification to CHECKSUM, and to then switch TDE back on. This resolved the problem.

    For more info on this, please refer to :

    http://social.msdn.microsoft.com/Forums/sqlserver/en-US/3b9ce14c-f21d-4fdb-baf2-d3dcb2bcf8c1/backup-with-checksum-against-an-encrypted-database-restore-fails?forum=sqldisasterrecovery

    https://connect.microsoft.com/SQLServer/feedback/details/622922/backup-with-checksum-produces-corrupt-backups-after-enabling-checksum-page-verification-on-an-encrypted-database

    Please note this issue is NOT fixed for SQL 2008 SP3 which is the version of SQL Server we experienced this problem with.

    Hope that helps someone out! 😀

Viewing 3 posts - 1 through 2 (of 2 total)

You must be logged in to reply to this topic. Login to reply