vSphere Storage Appliance

 View Only
  • 1.  disk alignment

    Posted Jun 24, 2010 08:14 AM


    I am using a netapp fc attached san and vsphere 4 U2 hosts and understand that the vmfs partitions are aligned by default but i have a query regarding the disk alignment of the vm's and the esx hosts.

    The hosts are boot from san, do they need aligning to the lun somehow ?

    The guests are win 2003 and win 2008. from reading forums, win 2008 should be ok.

    With regards to the 2003 images though, im thinking I dont really want to have to manually align every image and was wondering if any knows if creating a template, aligning the template and then just deploying from that would automatically make all images deployed from it aligned ?

  • 2.  RE: disk alignment

    Posted Jun 24, 2010 08:30 AM

    Netapp delivers two tools for alignment, one for testing if the guest partition is aligned (mbrscan) and one to align it (mbralign).

    I guess it is worth testing it, even if W2K3 shopuld be aligned by default.


    VCP 3 & 4


    =Would you like to have this posting as a ringtone on your cell phone?=

    =Send "Posting" to 911 for only $999999,99!=

  • 3.  RE: disk alignment
    Best Answer

    Posted Jun 24, 2010 03:10 PM

    you are correct.

    Create a 2003 template, correctly align it using mbrscan and mbralign, then once you deploy from those templates, all VMs will be aligned.

    I think you're hosts are fine.

    here is a good article on how to run mbrscan and mbralign


  • 4.  RE: disk alignment

    Posted Jul 08, 2010 07:40 PM

    Cheers guys.

    I got the latest host utilities tools from netapp and ran the mbrscan and mbralign.

    The win 2008 images were all already aligned but the win 2003 were not.

    I aligned them and then cloned from them and the new images were still aligned which i'm glad about as it takes a while aligning the images.

  • 5.  RE: disk alignment

    Posted Jul 08, 2010 07:43 PM

    congrats. I'm still working on taking the time to take my VMs down for alignment.

    up next for you is reclaiming white space with SDelete :smileyhappy:

    Kendrick Coleman


    twitter: @KendrickColeman

  • 6.  RE: disk alignment

    Posted Jul 08, 2010 07:53 PM

    Not seen SDelete so did quick google and it just looks like a file shredder unless it's same name for somethign else.

    Most of my images are deployed thin provisioned as they won't be growing but I like to have a bit of spare space just incase. Also I have dedupe enabled on the netapp.

  • 7.  RE: disk alignment

    Posted Jul 08, 2010 08:03 PM

    I'm writing up a handy ISO currently and waiting back from NetApp to see if i can distribute the mbrtools as part of this set.

    SDelete is for thin provisioned disks.

    If you have a VM, that has a 100GB Disc, but you are only using 20GB, then only 20GB is seen. Well what happens when one weekend you need to put 30 more gigs on the drive. You now have a VM with 50GB of 100GB drive taken. The SAN see's this as 50GB. Next week, you delete those 30GB so your windows drive shows 20GB of 100GB, but your SAN still sees 50GB of 100GB. This is because you now have 30GB of whitespace. You have to run SDelete to re-claim that whitespace, then perform a storage vMotion.

    Best Blog post I found on it:


    Kendrick Coleman


    twitter: @KendrickColeman