In AOS 5.0, you can expand the disk online. In versions older than AOS 5.0, you needed to go offline to expand the disk and then online again. But before expanding the disk you will need to increase the size of the volume group. The size the disk in a volume group can be increased using the Prism GUI or the aCLI or nCLI. This article describes the increasing the size of the volume group disk using nCLI and aCLI and also shows how to expand the disk online in Windows guest OS.

Expand disk size of Volume Group through aCLI and nCLI

From aCLI:

Starting from AOS 5.x, the disk can be expanded without taking it offline.

Increase the size of the disk:

nutanix@cvm$ acli vg.disk_update <Volume Group name> <disk index> new_size=<size of disk>

Note:  when specifying the size, uppercase G is for gibibyte, lowercase g is for gigabyte.

From within aCLI, execute "help <command>" to get more information about commands, including optional arguments.

From nCLI:

Increase the size of the disk:

nutanix@cvm$ ncli volume-group update-disk uuid=<Volume Group UUID> index=<disk index> size-mib=<Size of disk in MiB>

Expand volume group disk size from Prism

In the Prism web console, do the following:

1. Click on Home tab and select Storage.

2. Under Table tab, click on Volume Group.

3. Select the disk entry that needs to be updated and click Update.

4. Click on the Edit button and specify the new size.

5. Click Save.

Note: You can only expand the size of the disk but cannot decrease the size of the disk. 

Increase disk size inside Windows

1. ​Log in to the guest OS.    ​

Note: In this solution, the OS is Windows.

2. Press Windows+R to open Run window and type diskmgmt.msc and click Ok. The Disk Management window opens.

3. Go to Action menu and click on Rescan Disks.

The new space shows as unallocated as shown in the following screenshot:

4. Right-click on the NTFS partition and select Extend Volume.

5. Select the amount of disk space you want to extend the volume by.

Expand volume group disk in Windows using storage spaces

To increase the virtual disk size of the storage pool in Windows 2012 or 2016, you need to add a new disk to the volume group. Due to the limitation of storage spaces you cannot extend the virtual disk by increasing the disk size of the volume group on the Nutanix cluster. Please check following article for information on how to add disks to storage pool: https://techcommunity.microsoft.com/t5/Core-Infrastructure-and-Security/Storage-Spaces-Understanding-Storage-Pool-Expansion/ba-p/256491

For portal documentation, please refer to: https://portal.nutanix.com/page/documents/kbs/details?targetId=kA03200000099cZCAQ