SQL Server Performance Forum – Threads Archive

DiskDefrag on Database servers

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

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
[email protected] When life gives you a lemon, fire the DBA.

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

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

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 â€œAS ISâ€ with no rights for the sake of knowledge sharing.

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