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Database mirroring : Transaction log space pressure RRS feed

  • Question

  • Hi,
    With database mirroring, if the mirror database fails, the transaction log space on the principal database cannot be reused even if we are taking transaction log backup. This mean we need to have enough space for the transaction log to grow or bring mirror database online before the logs fills up the availabale disk space or break the database mirroring.

    If we lost our principal database, and we force to switch on the mirror database with the "SET PARTNER FORCE_SERVICE_ALLOW_DATA_LOSS" command. After, the old mirror is now principal with the disconnected status because the old primary stil unavailable.

    During this time and until the old principal become mirror and online, do I have a transaction log space pressure on the new principal ?

    regards,

    Tuesday, March 5, 2013 5:08 PM

Answers

  • Hi Mohit,

    thanks for your answer.

    When you mention to take database out of mirroring state, do you mean to use this command in the new principal database ?

    alter database database_name set partner off;

    regards,

    Tuesday, March 5, 2013 6:57 PM

All replies

  • If your (old) principle server is out of service for extended period of service, you will have to rebuild mirroring.  Therefore in this case to make sure you don't have a transaction log that can't be reused.  Take database out of mirroring state would be recommended approach in this case.

    Cheers!


    Mohit K. Gupta --- MCTS, MCITP, MCC2011
    My Blog OpsVault My MSDN Blog Twitter @SQLCAN

    Tuesday, March 5, 2013 5:28 PM
  • Hi Mohit,

    thanks for your answer.

    When you mention to take database out of mirroring state, do you mean to use this command in the new principal database ?

    alter database database_name set partner off;

    regards,

    Tuesday, March 5, 2013 6:57 PM
  • Correct.

    Mohit K. Gupta --- MCTS, MCITP, MCC2011
    My Blog OpsVault My MSDN Blog Twitter @SQLCAN

    Tuesday, March 5, 2013 7:34 PM