Correction of Misaligned VM Disk

Hi All,

As we know in real IT world we need the speed and performance while accessing application and files . And  in world of virtual environment of servers we need this more, but there are some flaws come in to the picture while implementing 2003 server in virtual environment Here we will  discuss about the misaligned disk of VM servers and how to correct it...

What is VM Misaligned Disk.

When looking at performance problems traditionally storage is usually the first place many of us would look and for a good reason. In many of the environments these storage problems are caused by misaligned file systems. Why is that? Well fairly simple, misalignment causes overhead. Just look at this diagram:

If you look at the Guest OS and the Array, you will see that in order to read 1 Guest OS cluster the Array needs to read two chunks. With a single VM running on a datastore and your array the impact might not be severe but when you have dozens or hundreds running it will be substantial while it is completely unnecesarry.

How to correct VM Misalignment.

Before you begin:

Log into vCenter and Shut down the VM with misaligned disks.                                                         Rename the server to <server name-old>

  1.Start VMware vCenter Converter Standalone Client ver.5 with Run As administrator

  2.Select Convert Machine

   3. Select source type: VMware Infrastructure virtual machine

   Specify server connection information to vCenter server

 4.    Ignore Security Warning

 5.    Select VM with misaligned disks

6.    Select destination type: VMware Infrastructure virtual machine

Specify VMware Infrastructure server details for vCenter

 7.Ignore Security Warning

 8.  Enter the original server name as destination and put it in the correct folder

 

9. Select destination host and datastore.

NB! The datastore can not be the same as source

  10.  Edit Data to copy

11.      Data copy type: Select volumes to copy and click Advanced ->Destination Layout

 12.  Select Thin provisioning for all disks

Select correct datastore

Select Ignore page file and hibemation file

Select Create optimized partition layout

 13.   Verify and Click Finished to start

 14.     When the job  completed log into vCenter and verify that the new aligned VM is using the same network adapter and connected to the same network label as the original misaligned VM. If not, this has to be corrected before you can power on the new aligned VM.

 15.    Power on the new aligned VM and verify that all disk are aligned

From command prompt run: wmic partition get Index, Name, StartingOffset

Misaligned disk will have StartingOffset 32256

Aligned disk will have StartingOffset 32768 , 1048576 or amy other StartingOffset dividable with 4096

After you finish

When the customer has verified that the new aligned VM is ok, delete the original misaligned VM named <server name-old>.