How to align Windows disks in VMware with Netapp disk

alertWarning: Always have a backup before you perform disk alignments in windows

How to check Drive alignment in windows:

  1. run “System Information” (msinfo32.exe in Start-> Run)
  2. and select Components .. Storage .. Disks
  3. scroll to the bottom and you will see the Partition Starting Offset information.
  4. This number needs to be perfectly divisible by 4096.
  5. The default .vmdk, you will see the Partition Starting Offset set to 32,256  (32,256 / 4096 = 7.875)
  6. and thus this file system is not correctly aligned.

 Align C Drive

To do this after a P2V or after the fact to use mbrscan and mbralign in the ESX console to align, you will need to go to the host the VM is running on to do the steps (not for ESXi because they are part of netapp host tools that needs to be installed)

New VM

create your vm and use a boot disk before you install the OS to align the disk (follow align other disk section)

How to align other windows disks

alertImportant warning: If you do these steps on C drive you will lose your data

Note: if you have a misaligned disk you will need to create a new disk perform the steps and migrage the data, After you have added a new disk to your VM and NOT formated it follow the below steps, this might work with the align C drive steps to save recreating and migrating data, but have not tried it.

  1. CMD>diskpart
  2. DISKPART> list disk (disks should be listed)
  3. DISKPART> select disk # (This selects the disk drive)
  4. DISKPART> list partition (This step should result in a message stating “There are no partitions on this disk to show.” This message confirms the disk is blank)
  5. DISKPART> create partition primary align=64
  6. Viewing the disk using “System Information” the Partition Starting Offset is now 65,536… 65,536 / 4096 = 16, and thus this file system is properly aligned to the storage blocks.
  7. Format it

Another note: is currently VMware converter does not align your harddrives this will need to be done after you do your P2V, and you do not need these steps for Windows 2008 it should be aligned from the install.


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