How to Expand a Virtual Machine Disk or Add New Disks in VMware, VirtualBox, Hyper-V

In this article, we’ll explore how to expand a disk and how to add new disks in such virtual machines as VmWare, VirtualBox, HyperV. When a new virtual machine is created, you also create a virtual hard disk for it, and you specify the disk size in the settings. However, as you work with the machine, it may turn out that this disk size is not enough for your needs. What should you do in this case? How to increase the size of an existing disk?

How to Expand a Virtual Machine Disk or Add New Disks in VMware, VirtualBox, Hyper-V

Before you start doing the things described below, I strongly recommend backing up your virtual hard disk file.

VMware Workstation

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🔷 How to Expand a Virtual Machine Disk or Add New Disks in VMware, VirtualBox, Hyper-V 🔷

🔷 How to Expand a Virtual Machine Disk or Add New Disks in VMware, VirtualBox, Hyper-V 🔷

VMware Workstation is quite a popular tool for working with virtual machines. It has a good graphical interface, and it is simple and convenient enough for personal use.

Here is a video about creating a VMware virtual machine:

To expand the disk, start VMware Workstation:

Select the necessary virtual machine, click on the Virtual Machine button, then click on click on the Settings menu.

Access the virtual machine settings

Now choose the Hardware tab and click on the Hard Disk option. In the menu on the right, find the Expand disk capacity option. Click Expand next to it, then OK. Now specify the new disk size and click Expand.

Expanding the disk

After some time, the program will inform you that the disk was successfully expanded.

The disk was successfully expanded

After that, power on the virtual machine and check the disk capacity in the Disk Management window. Now you need to extend the volume on the virtual machine. Right-click on the disk and choose Extend Volume, add the required amount of space and click Next; the disk is extended but all the data is still intact.

Extending a volume in Disk Management on a virtual machine

Also, if the original size of the hard disk is insufficient, you can add one more virtual disk. You can both add an existing disk or create a new one.

To do it, power off the virtual machine, and click “Edit virtual machine settings” in the information page. In the Hardware tab, select the Hard Disk option and click Add below.

Adding a disk to the virtual machine

It starts the Add Hardware Wizard. Select Hard Disk and click Next. Leave the predefined setting as it is and click Next again.

Add Hardware Wizard

In this Select Disk window, you can give a path to an existing virtual disk, or create a new virtual disk. In my case, I’ll be creating a new one, so I click Next.

Creating a new disk to add to the virtual machine

At the next step, set the virtual disk capacity and choose the option Store the virtual disk as a single file, and click Next.

The option to store the virtual disk as a single file

Give the path and name for this disk, click Finish. The virtual hard disk is now created and displayed on this list. Click OK to leave the settings.

The option to store the virtual disk as a single file

After that, the operating system recognizes the freshly created virtual disk as an unallocated space without partitions. We’ll fix it by initializing the disk. Click on the Start menu and go to Disk Management. The integrated utility has detected the new disk automatically and suggested to initialize it, so click OK.

The operating system recognizes our freshly created virtual disk as an unallocated space without partitions

Go back to the utility window. Click on the disk with unallocated space and choose New Simple Volume, click Next, give the volume size, choose a disk letter and click Next.

New Simple Volume

In the next window you can change the volume label; click Next and Finish, which formats the disk and makes it ready to use.

Change volume label

Oracle VirtualBox

When creating a virtual machine in the VirtualBox tool, it is difficult to calculate the exact disk space you will need after the operating system is installed. There are two methods of adding free disk space to the virtual machine without removing its data and the virtual machine image itself.

Beginning with VirtualBox 6.0, we can use the graphical feature for resizing virtual disks. To use it, start the program, go to the File menu / Virtual Media Manager.

Virtual Media Manager

Next to the operating system, you will see the disk virtual size. Select your virtual machine, and then drag the slider, or just type the required size in this field and click Apply.

Type the required disk size

Close the Virtual Media Manager and start the operating system. Extend the volume with the help of Disk Management in Windows as shown in the previous example.

If you have a different version of VirtualBox (older than version 6.0), then you need to use the VBoxManage command in the command prompt to increase the disk size.

Before you start, shut down the virtual machine and launch the command prompt as administrator.

Launch the Command prompt as Administrator

After that, navigate to the root folder containing the program and find a file with the name VBoxManage.exe, right-click on it and copy its path.

Copy the file path

Then switch to the command prompt, paste this path and add this command: modifyhd.


Now you should give the path to the existing virtual disk, the size of which you need to increase. Go to the folder where your disk is stored and copy its path, paste it into the command prompt and type the command resize, adding the necessary amount of additional disk space.

Add the amount of additional disk space

After that, switch to the program and run the guest OS to extend the volume in the same way as we did it in the previous method. Now that the disk has increased in size, you can continue your work.

If this disk runs out of free space soon, you can add – or even create – a second disk to store your data. You can do it quite easily. Switch to the program, select the required virtual machine, then access its settings, open the Storage tab. Next to the SATA Controller tab, click on the Add button.

Adding a disk

You can add an existing disk or create a new one. For the latter option, click on Create, don’t change anything in the wizard window and just click Next. Choose a dynamically allocated disk so that it takes less space.

Creating a dynamic disk

Specify disk location and size, and then click Create. Find your disk on the list and click Choose, so the new disk will be added. Click ОK and run the virtual machine.

Specify disk location and size

In the virtual machine, the disk will be empty and without any file system. You will have to initialize the disk just like we did it before.

Microsoft Hyper-V

The last program we’ll be exploring today is Hyper-V. The opportunity to change disk size dynamically has been available in Hyper-V since Windows Server 2012 R2. The feature called Online VHDX Resize lets you increase or reduce the size of a virtual disk.

You can modify the size of any Hyper-V disk, be it fixed-size or dynamic. To do it, open Hyper-V virtual machine manager, select the required virtual machine, open Settings, choose a virtual disk and click on the Edit button.

Hyper-V virtual machine manager

In the wizard window that opens, choose Expand and give the new size for the hard disk.

Choose Expand

Now start the guest OS, open the Disk Management panel. There is an unallocated area on the disk. Click on the volume that needs to be extended. Keep in mind that you can only extend the volume which is located on the left of the unallocated space. Now this disk has increased in size.

Disk Management panel

Also, you can modify the size of a VHDX disk with PowerShell. You need to get a full path to the virtual machine disk. Go to Hyper-V Manager, click on the virtual machine, go to Settings, look at the SCSI Controller tab: by clicking on the disk, you can see its path. Copy it.

Copy the full path to Hyper-V virtual disk

Run PowerShell as administrator, type the command Resize-VHD -Path and paste the path to the virtual machine disk; after that, add the command -SizeBytes and give the required size to which the disk should be expanded. Remember that if you give a virtual disk size smaller than the actual space it occupies on the disk, you will get an error. After that, you’ll have to extend the volume in the Disk Management tool.

Resize-VHD -Path

Just like with all other hypervisors we have explored today, in Microsoft Hyper-V you can add a virtual hard disk or create a new one. To create a new virtual disk, start Hyper-V Manager, right-click on the virtual machine and open its settings. In the SCSI tab, specify the disk type and click Add, and then click New.

Adding a new disk to the virtual machine

In the New Virtual Hard Disk Wizard, click Next. At the second stage, select Fixed size. Give the disk name and path, and at the final stage, click Finish and Apply.

New Virtual Hard Disk Wizard

When you start the virtual machine, the new disk should be initialized and partitioned so that you can use it in your work. Just follow the same procedure for initialization as before.


Also, I would like to remind you: if you have lost your virtual machine data for any reason, you can visit our channel to find a good video about recovering virtual machine data.

Vladimir Artiukh

Author: , Technical Writer

Vladimir Artiukh is a technical writer for Hetman Software, as well as the voice and face of their English-speaking YouTube channel, Hetman Software: Data Recovery for Windows. He handles tutorials, how-tos, and detailed reviews on how the company’s tools work with all kinds of data storage devices.

Oleg Afonin

Editor: , Technical Writer

Oleg Afonin is an expert in mobile forensics, data recovery and computer systems. He often attends large data security conferences, and writes several blogs for such resources as, Elcomsoft and Habr. In addition to his online activities, Oleg’s articles are also published in professional magazines. Also, Oleg Afonin is the co-author of a well-known book, Mobile Forensics - Advanced Investigative Strategies.

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