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Using SQlExpress at witness in DB mirroring RRS feed

  • Question

  • I want to use SQlExpress 2005 as witness , while mirroing SQLServer 2005 DB in High Availability -Autimatic failover mode

    I see in the forum , some say, SQlExpress has memory constraint , so not good to use, where as someother say memory does not matter since it is used just as witness , it will not store any data and so on.

    wondering , which assumption is correct ?

    My data is much much > 4GB  which is the limit of SQlExpress I suppose.

    So, can I use SQlExpress as witness without any issues in the field ? Does it smoothly handle the automatic failover when needed ?

    Monday, March 7, 2011 9:47 PM

Answers

  • Please find this link that describes

    http://technet.microsoft.com/en-us/library/ms175191.aspx

     

    Witness in SQL Server 2005 express should work since its used for Quorum purpose and nothing to do with data storage.

    Regards,
    Zainu

    • Proposed as answer by WeiLin Qiao Thursday, March 10, 2011 2:21 AM
    • Marked as answer by WeiLin Qiao Wednesday, March 23, 2011 9:47 AM
    Monday, March 7, 2011 10:48 PM
  • Durga,

    in my opinion

    Role of witness is proxy between principal and mirror and (think of it  as a liasion officer) that determines when automatic failover occur. Per MS documentation it does not matter what hardware configuration witness server is runing as long as it can run SQL Express it should be fine

    • Proposed as answer by WeiLin Qiao Thursday, March 10, 2011 2:21 AM
    • Marked as answer by WeiLin Qiao Wednesday, March 23, 2011 9:47 AM
    Monday, March 7, 2011 11:05 PM
  • None of the above answers are complete . All were saying that it "should" work based on their assumptions.

    Anyways, We have experimented using SQlExpress as witness with the mirroring DB >4GB , and works fine. !

    So, yes SQLExpress can be used as witness !

     

    Durga


    Durga Arikapalli
    Thursday, March 24, 2011 1:48 PM

All replies

  • I want to use SQlExpress 2005 as witness , while mirroing SQLServer 2005 DB in High Availability -Autimatic failover mode

    I see in the forum , some say, SQlExpress has memory constraint , so not good to use, where as someother say memory does not matter since it is used just as witness , it will not store any data and so on.

    wondering , which assumption is correct ?

    My data is much much > 4GB  which is the limit of SQlExpress I suppose.

    So, can I use SQlExpress as witness without any issues in the field ? Does it smoothly handle the automatic failover when needed ?

     

     

    • Merged by WeiLin Qiao Thursday, March 10, 2011 2:17 AM Duplicated
    Monday, March 7, 2011 9:46 PM
  • SQL Express is just used as a witness, so  4 GB ( starting with SQL Express 2008 R2 it is 10 GB) limitation on disk space (for each database) would not even matter. Try to keep express with same version as principal and mirror so ifyou are using SQL 2008 use 2008 express.

    >>Does it smoothly handle the automatic failover when needed? 

    Yes and it is supported.

    • Proposed as answer by SQLWork Tuesday, March 8, 2011 9:52 PM
    • Proposed as answer by WeiLin Qiao Thursday, March 10, 2011 2:21 AM
    Monday, March 7, 2011 10:13 PM
  • thanks . See the thread below. it speaks contradictory

    http://social.msdn.microsoft.com/Forums/en/sqldisasterrecovery/thread/ec13ebc7-0ad5-4330-8dc3-39030cd29d59

    so wonder which statement is correct .


    Durga Arikapalli
    Monday, March 7, 2011 10:20 PM
  • Please find this link that describes

    http://technet.microsoft.com/en-us/library/ms175191.aspx

     

    Witness in SQL Server 2005 express should work since its used for Quorum purpose and nothing to do with data storage.

    Regards,
    Zainu

    • Proposed as answer by WeiLin Qiao Thursday, March 10, 2011 2:21 AM
    • Marked as answer by WeiLin Qiao Wednesday, March 23, 2011 9:47 AM
    Monday, March 7, 2011 10:48 PM
  • Durga,

    in my opinion

    Role of witness is proxy between principal and mirror and (think of it  as a liasion officer) that determines when automatic failover occur. Per MS documentation it does not matter what hardware configuration witness server is runing as long as it can run SQL Express it should be fine

    • Proposed as answer by WeiLin Qiao Thursday, March 10, 2011 2:21 AM
    • Marked as answer by WeiLin Qiao Wednesday, March 23, 2011 9:47 AM
    Monday, March 7, 2011 11:05 PM
  • Hi Durga,

    Your query is answerd by Chirag Shah in the following post http://social.msdn.microsoft.com/Forums/en-US/sqlexpress/thread/8372e906-a7fe-416f-9bc6-422f7b05cc20 .

    This is a duplicate thread . Please close this post .

    ---------------------
    Thanks,Suhas V

    Tuesday, March 8, 2011 5:27 AM
  • None of the above answers are complete . All were saying that it "should" work based on their assumptions.

    Anyways, We have experimented using SQlExpress as witness with the mirroring DB >4GB , and works fine. !

    So, yes SQLExpress can be used as witness !

     

    Durga


    Durga Arikapalli
    Thursday, March 24, 2011 1:48 PM