When you create VDI desktop assignments, you assign an initial capacity of VDI desktop instances using the Max Desktops value. As the user population changes, you might need to expand or shrink the VDI desktop assignment.

You would expand a VDI desktop assignment by adding additional desktop VMs to meet your end user needs.

You would shrink a VDI desktop assignment to free up capacity in your Microsoft Azure cloud environment so you can use that capacity for something else. When your end users no longer need to access the desktop VMs from a particular VDI desktop assignment, you might want to free up that unneeded capacity.

Important: For a dedicated VDI desktop assignment, to reduce its capacity, you must delete the desktop VMs from the Desktops tab in the assignment's details page. You cannot shrink an existing dedicated VDI desktop assignment by decreasing the Max Desktops value.

Expanding a VDI Desktop Assignment

You increase the capacity of a VDI desktop assignment by adding VDI desktop VMs to the VDI desktop assignment. You add desktop VMs by editing the VDI desktop assignment, floating or dedicated, to increase the Max Desktops value. See Edit an Assignment in Your Horizon Cloud Environment for how to edit a VDI desktop assignment using the Horizon Universal Console. You can expand an assignment up to the scale limits for VDI desktops in a pod.

When you submit the change, the system starts creating the new desktop VMs to match the new larger Max Desktops value. You can use the VDI desktop assignment's Desktops and Activity tabs to monitor the process. For details about those tabs, see Viewing the Assignments Currently Configured in Your Horizon Cloud Environment.

Shrinking a VDI Desktop Assignment

The method to reduce capacity in a VDI desktop assignment varies depending on which type it is.

VDI Desktop Assignment Type Description

To reduce the capacity of a floating VDI desktop assignment, edit the assignment and change Max Desktops value to a new smaller value. When you submit the change, the system starts to delete not-in-use VDI desktop VMs until the total number in the assignment matches the new value.

If the new requested number is smaller than the number of not-in-use desktop VMs due to currently logged-in end users or because end users have disconnected sessions to the desktop VMs, the system prevents the process and an error message displays in the console. To shrink the assignment in this situation, you can use one, or a combination, of the following methods:

  • Re-edit the assignment and use a different Max Desktops value to remove any currently not-in-use desktops.
  • Wait for, or force, the users to fully log off of the in-use desktops before you edit the assignment to reduce the Max Desktops value. you can force a log off from the assignment's Desktops tab by selecting the desktop and clicking ... > Log Off.

Because the desktop instances in a dedicated VDI desktop assignment are mapped to specific end users when they first connect to a desktop from the assignment, the system prevents reducing the capacity of the assignment by changing the Max Desktops value. The reason is because reducing that number would not inform the system about which specific desktop instances to delete out of the total number.

To reduce the size of the dedicated VDI desktop assignment, you must explicitly delete desktops from the assignment's Desktops tab. On that tab, select the check box next to the desktops you want to delete, click > Delete, and confirm the deletion. You can delete both VDI desktops that are assigned to users and unassigned ones.

  1. Take the dedicated VDI desktop assignment offline using the Assignment page's Take Offline button. Taking the assignment offline prevents the system's power management feature from attempting to automatically create new desktop VMs as you delete some.
  2. Select the check box next to the desktops you want to delete, click > Delete, select Yes under 'Reduce assignment size' in the dialog, and confirm the deletion.
  3. When the system has finished deleting the desktops, bring the assignment back online again using the Bring Online button.

After the system has deleted the selected VDI desktops, the assignment's size automatically decreases down to the number that matches the original Max Desktops value minus the ones you deleted.

Note: You cannot delete a desktop that the Desktops tab indicates has an active or disconnected session. That end user must be fully logged off before you can delete that desktop.

If you want to keep the same overall capacity of the dedicated VDI desktop assignment, but want to have a different user consume a desktop that is already mapped to a user, on the assignment's Desktops tab, you can select the desktop and select > Unassign. Then you can explicitly assign that desktop to another user.