If you have been using VirtualBox then this is a commonly asked question – How to increase VirtualBox disk size after it has been created? Once you have created your virtual machine and allocated some hard disk space, you may want to increase VirtualBox disk size at a later point in time. This scenario usually happens when you install your operating system, other required software’s, only then you find there is a shortage of disk space.

Though this article looks a little brief, it is a two step process and is very easy, so do not get scared. Just follow the steps and you will see how easy it is. But before we get started let us keep the following things in mind.

  1. With this command you can just increase the size of the VDI but not shrink it.
  2. This works only for dynamically allocated disks and that too only for VDI & VHD formats.

Step1: Use VBoxManage to Increase VirtualBox Disk Size Logically

VBoxManage is the command-line interface to VirtualBox using which you can perform all operations that you perform via the GUI and even more. Let us quickly see how to increase the size of the existing Virtual Disk Image (.vdi) that you have already created.

  • Launch the VBoxManage command-line interface, using the below steps:
  • Open command prompt from Run window.
  • Navigate to the path where you have installed the VirtualBox from the command prompt, default path is C:\Program Files\Oracle\VirtualBox\

Navigate to VirtualBox Path

Now let us test a basic VBoxManage command before we increase the VirtualBox disk size.

VBoxManage startvm “YourVMName”

If the above command starts your Virtual Machine then you are good to go. Now that the VBoxManage command is working, let us see use the command to increase VirtualBox Disk Size.

Note: Please take a backup of your existing VDI file before performing the below steps.

Scenario: In my case I had earlier assigned 25 GB to my Virtual Machine so I planned to revise it as 100 GB.

The modifyhd VBoxManage command helps you to increase VirtualBox size by using the –resize option. Below is the syntax for using the command.

VBoxManage modifyhd <VDI_FILE_PATH> – – resize <NEW_SIZE>

You can get the VDI_FILE_PATH from the General Tab under VirtualBox Settings (CTRL + G), if you have more than more VDI file then provide the appropriate file name. Specify the NEW_SIZE in MB.

Example: VBoxManage modifyhd D:\Nivitha_VM\NivithaSree\NivithaSree.vdi –resize 102400

You should see something as shown below once the command has been successfully executed.

resize command to Increase VirtualBox Disk Size

Though you have executed the command you wouldn’t see any effect on the existing disk of our virtual machine. We need to use partition management tool in order to fully utilize the space that we have increased. So let us quickly see how to do that.

STEP 2: Use Disk Management Tool to Increase VirtualBox Disk Size Physically

  • Go to Start Menu, and type Disk Management in the Search Program and Files text box. You should see the create and format hard disk partitions option, Click to launch it.

Launch Disk Management Tool

  • On the Disk Management window, right click on the drive for which you would like to increase the disk space and click Extend Volume… option.

Click Extend volume on drive

  • You should see the Extend Volume Wizard launched as shown in the below screenshot. Click Next.

Extend Volume Wizard

  • In the Select Disks screen you should see the remaining space that is available for you to add to the existing disk. In my case it is 75 GB.

Just click Next

  • Click Finish to complete the Extend Volume operation.

Extend Volume Wizard Final Step

  • As you can see from the below screenshot the total capacity of C drive is now 99.90 GB.

Disk Management Screen after extending

Hope you learned how to increase VirtualBox Disk Size, if you found this article useful kindly share it with your circle.