Hyper-V, Windows Server 2012

Are you fed up with the VHDX disk expansion?

Here is a free solution from Systola I used to make VHDX disk expansion life easier.

It’s a common requirement always to increase the disk size, when you want to create more Exchange Databases in a vhdx based disk or a temporary space requirement during your database defragmentation/mailbox move etc.

Traditional method in a Hyper-V environment is go to the VM properties and set the expansion size and wait for hours and hours !! (If you want to expand in TBs)


Most of the production infrastructures won’t be in a position to give such kind of downtime of the live system. In my case, it was expected to have 20Hours of downtime for a 10TB expansion !!!.

How about, anything which can do the task in seconds 🙂 How the tool achieve this kind of miracle is as they mentioned: ‘This tool did not zero-out the new disk, thus it was lightning fast even while creating multi-gigabyte and terabyte-sized VHDs’. If you can afford this condition, go and download vhdxtool.exe:

I actually followed the method as below:

  • Shutdown the Virtual Machine with vhdx disk you wish to expand.
  • Expand the LUN at your storage. It can be EMC or a local disk
  • From the Hyper-V owner node, refresh disk management to show the added space.
  • Right-click the volume and extend to allocate the added space to the current volume.


  • Go to the folder in which you extracted the tool (Eg:C:\vhdxtool\vhdxtool.exe)
  • On the owner node, open PowerShell in Administrator mode and run “C:\vhdxtool\vhdxtool.exe extend -f <path to vhdx file> -s <new disk size>”. When you are working with huge TBs, it can expand the Block Allocation Table too. Otherwise, you can’t be able to see the additional message.


  • Power on the Virtual Machine
  • On the disk management console of the Virtual Machine , make sure that you got the disk expanded. If it’s not, you may want to expand it from there again (Some Hyper-V phenomenon when you use the disk as shared). Right-click the volume and extend to allocate the added space to the current volume.

So, let’s make our life easier with SYSTOLA’s vdhxtool. Thanks SYSTOLA 🙂