SQL Server Performance

mdf and ldf files not clustered?

Discussion in 'SQL Server 2005 Clustering' started by NewDBA, Feb 27, 2007.

  1. NewDBA Member


    I have 2 physical servers and 1 Disk array controller.

    SQL Server was installed from the 1st node and recreated itself on node2

    Currently when I shutdown node1 the node2 will take over with no problem.

    But problem that I am facing is that my system and user databases are basicaly in one
    spot : the very same disk aray holds mdf and ldf files for node1 and then when
    node2 is becoming active it will be talking to the same mdf and ldf files.

    Is that what I suppose to have , should I have bought 2nd disk array controller to set up proper clustering environmemt? Or there is a way to configure sql so I have
    clustering mdf and ldf files as well?

    Thank you
  2. Argyle New Member

    Microsoft clustering is a failover cluster, there is no data replication going on at disk level. It is correct that the second node takes over the same disks and mdf/ldf files. The second node does the same with the sql server ip and name as well.
  3. satya Moderator

    As referred by Argyle clusetering is based on the server level and it will take care of allowing the application once the failover is completed successfully, you need not worry about providing any additional mirroring for the database. You might also look at the database mirroring in SQL Server 2005 to provide on any specific database.

    Satya SKJ
    Microsoft SQL Server MVP
    Writer, Contributing Editor & Moderator
    This posting is provided AS IS with no rights for the sake of knowledge sharing. The greatest discovery of my generation is that a human being can alter his life by altering his attitudes of mind.
  4. MohammedU New Member

  5. NewDBA Member

    Ok -thank you very much.

    That is exactly what I did : active/passive.

    Now we also have bought an other system : 2 servers ( for sql ) and 2 sans.

    Geograficaly 1sql server + 1SAN will be located in one building and
    an other sql server + SAN will be located in different building.

    I guess I will have to configure active/active clustering.

    Now If I understand that correctly , i will have to
    install active/passive environmetn on SQL1
    install active/passive environment on SQL2

    And then - I am not sure exectly how- but those 2 active/passive environment will somehow
    know about each other? And this is what we call active/active?

    Please help with that - maybe some good article - I cannot find anything clear enough.
  6. Argyle New Member

    No that is not what is called active/active.

    Active/active just mean that you have multiple instances in the same cluster and some of them are running on node 1 and some on node 2. If you moved all instances over to one node the other would be called passive. This affects SQL licensing.

    There is no data replication going in a microsoft SQL cluster, be it active/passive or active/active.

    You would have to look at database mirrorng, replication or log shipping. The procedure for setting up that is the same be it stand alone servers or clusteres you are replicating between.
  7. NewDBA Member


    I guess I don't understand how to install that active/active.

    1.May I say that because I have 2 separate SAN connected to each sql ( SQL1+SAN1 and SQL2+SAN2) I can only have active/active?

    2. May I say that because I have to separately install SQL server on SQL1 and install SQL server on SQL2 ( 2 instances) and during this install I specify 2 diff. name for virtual servers - this itself define that i install active/active

    3. May I at all install active / passive environment if I have 2 diff. geografic locations for SQL1+SAN1 and SQL2+SAN2 ? Or because of that it is not possible?

    4.I guess active/passive is better for performance?
  8. MohammedU New Member

    Now it is not called anymore as Active/Active cluster...It is called multi instace..
    Read the following article to know how to install..

    Active/Active clusters in SQL Server
    By Hilary Cotter, Contributor

    Read SQL Server 2005 Books Online topic "Failover Clustering "


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