SQL Server Performance

DiskDefrag on Database servers

Discussion in 'Performance Tuning for Hardware Configurations' started by akothand, Apr 27, 2006.

  1. akothand New Member

    Our DB server is SAN attached. When i ran the DiskDefrag "analyze" utility, it showed a major portion in RED.

    My doubt is : By concept, i understand that DiskDefrag moves the pieces of each file or folder to one location on the volume, so that each occupies a single, contiguous space on the disk drive. BUT, Has anyone used this in SAN drives and found any performance improvement.

    Thanks a lot

    Thanks,
    Anand.K

    Purity, patience, and perseverance are the three essentials to success
    and, above all, love - Swami Vivekananda
  2. derrickleggett New Member

    DO NOT run disk defrag against those SAN drives. Especially, if you are using LUN's that span multiple groups.

    Check with your vendor. They should have an analyzer tool, which will let you see the performance and "fragmentation" at the SAN level. Usually, it's not an issue and is managed internally by the SAN.

    MeanOldDBA
    derrickleggett@hotmail.com

    When life gives you a lemon, fire the DBA.
  3. joechang New Member

    the advantage in having a file in contiguous blocks is to allow for fast sequential access.
    SAN drives don't seem to benefit from sequential access so there will not be a gain on this
  4. akothand New Member

    thanks a lot for your inputs guys. I would try to run the Defrag on local C: drive at least then.
    (Even that is heavyly fragmented). Hope that will not be an issue in a clustered server.



    Thanks,
    Anand.K

    Purity, patience, and perseverance are the three essentials to success
    and, above all, love - Swami Vivekananda
  5. satya Moderator

    Do you think that is necessary or do you have any performance issue with disk?

    Satya SKJ
    Microsoft SQL Server MVP
    Contributing Editor & Forums Moderator
    http://www.SQL-Server-Performance.Com
    This posting is provided “AS IS” with no rights for the sake of knowledge sharing.

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