VMware ESX vSphere resize disk

Every now and then I need to resize (usually extend/enlarge) a disk attached to a Virtual Machine. I have tried several methods to do this over the years (including combinations of VMware Converter, third party partition manager apps, diskpart etc) but none have been as efficient as the method I discovered during recent VMware training for my VCP4 exam.

One of the new features of vSphere is the ability to resize disks without having to shut down the Virtual Machine. This was previously impossible in VI3. This greatly speeds up the resizing process which can be executed in a couple of stages:
1) Use the vSphere Client to edit the settings of the Virtual Machine in question. Select the hard disk and modify it's provisioned size as appropriate. Click OK to apply these changes - resizing the .vmdk file.
2) Verify that the .vmdk has been resized by opening the Management Console -> Disk Management to find the unallocated space on the disk that resides in the .vmdk (distinguished by the black colour in the legend at the bottom.) In this case you can see I have increased the size by 5GB.

Right click on the disk (in this case 'Disk 0') and select properties. On the Volumes tab make a note of the unallocated space, in my case it is 5122MB.

If you are using Windows Server 2003 or earlier versions of Windows (Note: Windows Server 2008 now allows you to resize a disk through Disk Management in the Computer Management Console/Server Manager even if this disk is the Boot/Page File disk) download Dell's EXTPART and extract it on the server that contains the disk you want to resize. Navigate to c:\dell\ExtPart (the default extracted location) and run extpart.exe. When prompted enter the the Windows drive letter of the disk on the Virtual Machine e.g. c:. When prompted for the size to extend the partition by enter the number noted down earlier (I used 5122 in this example.) After doing so the disk should be resized. You can check this by opening the Management Console -> Disk Management and verifying the size of the partition.


NB - If you receive the following error:

"Unable to connect to c: or it does not exist"

There are a couple of workarounds that you could try.
1) Close the Management Console (if it is open) and try extpart.exe again.
2) Try restarting the VM in safe mode and then run extpart.exe. This is not ideal but it is still easier than other methods I have tried to resize .vmdk files.