Configure Online Virtual Hard Disk Resize
Applies To: Windows Server 2012 R2
Starting in Windows Server® 2012 R2, Hyper-V provides you with the ability to grow or shrink the size of a virtual hard disk while the virtual machine is still running. This topic creates a virtual hard disk (attached to a SCSI Controller), adds the virtual hard disk to the virtual machine and details the process for expanding and shrinking a virtual hard disk.
Note
The user interface option to shrink a virtual hard disk is only visible for virtual hard disks that have been expanded previously. Online resize is exclusive to SCSI attached VHDX files. For more information about resizing virtual hard disks, see Virtual hard disk resizing.
Prerequisites
Before you attempt to edit the size of your virtual hard disk, make sure that you have the following:
A computer running Windows Server® 2012 R2 or later with the Hyper-V role installed.
A user account that is a member of the local Hyper-V Administrators group, or the Administrators group.
To create a virtual hard disk for a virtual machine
Create a virtual hard disk (attached to a SCSI controller) for a virtual machine using the following procedure:
On the Windows Start screen, click the Server Manager tile.
On the Tools menu, click Hyper-V Manager.
Under Virtual Machines, select the virtual machine.
In the Actions pane, click Settings.
Click SCSI Controller. On the right pane, under SCSI Controller, click Hard Drive.
Click Add.
On the right pane, under Hard Drive, click New.
On the Before You Begin page, click Next.
On the Choose Disk Format page, choose VHDX and click Next.
On the Specify Name and Location page, type the name of the new virtual hard disk. If required, type the location of the virtual hard disk. Click Next.
On the Configure Disk page, type disk size and click Next.
On the Completing the New Virtual Hard Disk Wizard page, click Finish.
Adding a virtual hard disk to the virtual machine
After adding a virtual hard disk, it is necessary to configure your virtual machine so that the operating system within the virtual machine can see the additional disk capacity. The disk must be brought online, initialized and formatted.
These instructions assume a virtual hard disk has been created for a Windows Server® 2012 R2virtual machine.
On the Windows Start screen, click the Server Manager tile.
On the Tools menu, click Hyper-V Manager.
Under Virtual Machines, double click to connect to the virtual machine.
Enter credentials and login to the virtual machine.
To start Disk Manager, start the Server Manager.
On the Tools menu, click Computer Management.
Under Storage, click Disk Management.
On the middle pane, locate the new hard disk. Right click the disk and click Online.
On the middle pane, locate the new hard disk. Right click the disk and click Initialize.
On the Initialize Disk page, click OK.
On the middle pane, right click the unallocated volume and click New Simple Volume.
In the New Simple Volume Wizard, click Next.
On the Specify Volume Size page, click Next.
On the Assign Drive Letteror Path page, click Next.
On the Format Partition page, click Next.
On the Completing the New Simple Volume page, click Finish.
The new virtual hard disk will now be visible to the virtual machines operating system.
To expand the size of a virtual hard disk
You can expand the storage capacity of the virtual hard disk using the following procedure:
On the Windows Start screen, click the Server Manager tile.
On the Tools menu, click Hyper-V Manager.
Under Virtual Machines, select the virtual machine with the virtual hard disk that you want to expand.
In the Actions pane, click Edit Disk to start the Edit Virtual Hard Disk Wizard.
On the Before you Begin page, click Next.
On the Locate Virtual Hard Disk page, click Browse.
Navigate to your virtual hard disk. Select your virtual hard disk. Click Open.
Click Next.
On the Expand Virtual Disk page, enter the new virtual hard disk size. The size is specified in gigabytes with a maximum size of 64TB for any virtual hard disk.
Click Next.
On the Completing the Edit Virtual Hard Disk Wizard page, click Finish.
Expand the volume of a virtual hard disk connected to a virtual machine
After expanding a virtual hard disk, it is necessary to configure the disk management within your virtual machine operating system so that it can see the new disk space. This space is currently residing as an unallocated volume created in the virtual disk.
These instructions assume a virtual hard disk has been expanded and that it is connected to a Windows Server® 2012 R2virtual machine.
On the Windows Start screen, click the Server Manager tile.
On the Tools menu, click Hyper-V Manager.
Under Virtual Machines, double click the virtual machine.
Enter credentials and login to the virtual machine.
To start Disk Manager, start the Server Manager.
On the Tools menu, click Computer Management.
Under Storage, click Disk Management.
On the middle pane, locate the existing volume in use by the virtual machine.
Right click the disk and click Extend Volume.
On the Welcome to the Extended Volume Wizard, click Next.
On the Select Disk page, click Next.
On the Completing the Extended Volume page, click Finish.
The operating system within the virtual machine will now see the expanded disk capacity.
To shrink the size of a virtual hard disk
You can shrink the size of a virtual hard disk. However, you cannot shrink the size of the virtual hard disk below the size of the disk volume that is in use within the operating system of the virtual machine.
Reduce the storage capacity of the virtual hard disk using the following procedure:
On the Windows Start screen, click the Server Manager tile.
On the Tools menu, click Hyper-V Manager.
Under Virtual Machines, select the virtual machine with the virtual hard disk that you want to shrink.
In the Actions pane, click Edit Disk to start the Edit Virtual Hard Disk Wizard.
On the Before you Begin page, click Next.
On the Locate Virtual Hard Disk page, click Browse.
Navigate to your virtual hard disk. Select your virtual hard disk. Click Open.
Click Next.
On the Choose Action page, click Shrink. Click Next.
On the Expand Virtual Disk page, enter the new virtual hard disk size. The size is specified in gigabytes.
Click Next.
On the Completing the Edit Virtual Hard Disk Wizard page, click Finish.