I was combing through the VMTN community forums and came across a couple of posts on the best way to extend or expand a vmdk file.  This topic seems to come up on a regular basis, so I thought it might be a good idea to put together a blog on this topic.

The main tool that I have used to complete this task is the Microsoft utility called Diskpart.  For most cases this utility will do the job just fine but it does have some limitations.  Inside of the vSphere client it is very easy to expand the vmdk file to the new size that you need.  Let’s take a quick look at the requirements to be able to extend a volume with Diskpart.

• The volume must be formatted with the NTFS file system.
• For Basic volumes, the unallocated space for the extension must be the next contiguous space on the same disk.
• For Dynamic Volumes, the unallocated space can be any empty area on any Dynamic disk on the system.
• Only the extension of data volumes is supported. System or boot volumes may be blocked from being extended, and you may receive the following error:

Diskpart failed to extend the volume. Please make sure the volume is valid for extending

• You cannot extend the partition if the system page file is located on the partition. Move the page file to a partition that you do not want to extend.

Even though you cannot extend the system or boot volume you can easy use a helper virtual machine to attach the disk you want to extend. You should then have no problems performing the extend with the helper virtual machine. Got to love virtualization!!!  I have found it just easier to use the helper virtual machine for any and all extends that I need to perform.

This is all pretty straight forward which brings me to my next question. What do you use when diskpart does not work or is there a 3^rd party tool that just really rocks?  Before moving on to 3^rd party it is worth mentioning another VMware product that can perform this talk for you also.  You can use vConverter to change the disk size during the conversion. This leaves vConverter as a very viable option to perform this task although it is one of the slowest options.

There is a tool call GParted from Sourceforge that is worth mentioning.  They have the ability to boot from a cd-rom or usb to extend volumes.  You can download this product straight from Sourceforge’s web site http://gparted.sourceforge.net/download.php

I found out from the forum that Dell has their own utility called ExtPart to be able to extend a volume.  More information on this tool can be found at http://support.dell.com/support/downloads/download.aspx?c=us&cs=19&l=en&s=dhs&releaseid=R64398&formatcnt=2&fileid=83929

So who has any others tools they use and would like to share with the class today? It would be great to have a reference of all the options and tools available to us.

ESX, VMDK, vmware, vSphere

This entry was posted on Tuesday, October 20th, 2009 at 7:45 am and is filed under vWire. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.