4 Replies Latest reply: Jan 27, 2016 11:09 AM by Nick Dyer RSS

    Defrag for Windows 2012 R2 Hyper-V CSV volume

    dbaddorf Newbie

         My Nimble customers have Cluster Shared Volumes (CSV) and run Windows 2012 R2 Hyper-V VM's on those CSV's.  My question is should I run Windows Defrag on the VM's?  And should I run Windows Defrag on the CSV volumes?  Running a defrag analyze on a CSV volume can be done (see http://blogs.msdn.com/b/clustering/archive/2014/01/02/10486462.aspx) but I am not seeing the output that I've been accustomed to - I don't see a message about "you should/shouldn't defragment this volume" but rather just see messages about Slab Consolidation.  Apparently Windows defrag works differently when the volume is thinly provisioned.  But I can't seem to find very clear information on the best practices of defragrmenting a CSV volume which is thin provisioned.  Which leads me to my above questions:  Should I run defrag at the VM level?  And should I run it on the CSV volume?

        I appreciate any insight that anyone has to offer...

      Thanks!  Dave

        • Re: Defrag for Windows 2012 R2 Hyper-V CSV volume
          Nick Dyer Pioneer

          Hi Dave,


          Wherever possible it's advisable NOT to run any defragmentation tools on a Nimble Storage platform. The CASL architecture has a built in defrag tool as part of it's garbage collection process (called sweeping) and is an always-on process running in the background of the file system; running a host-side defrag tool will merely change the layout of the blocks within the CASL architecture, leading to potentially worse performance overall.