Consider a scenario where before updating an entire pool with a new image, you would like to first try it out on a subset of the pool so that you know that the new image works, and users are able to login. This feature gives administrators an option to either update the entire pool or specify a set of virtual machines (VMs) to update. It allows a single desktop pool to support two images at the same time.

Patch Selected VMs In the Pool Using a Secondary Image

When you are using a secondary image, the workflow for the patching process is as follows:
  • Prepare a secondary golden image and snapshot based on the updated operating system image or applications.
  • Perform a push-image operation with the secondary golden image and snapshot. You have two options for this operation:
    • Publish the secondary image without immediately applying it to any machines in the pool.
    • Publish the secondary image and immediately apply it to selected machines in the pool.
  • After you have published the secondary image, options are enabled to apply either of the images to selected machines without using the Schedule Push Image process.

To patch selected VMs in the pool using the secondary image, perform the following steps.

  1. In Horizon Console, select Inventory > Desktops
  2. Click the pool ID.
  3. On the Summary tab, click Maintain > Schedule.

    The Schedule Push Image window opens.

  4. On the Image step, select the secondary image and snapshot to use.
    Note: If you are a VMware Carbon Black customer and select a golden image configured with Carbon Black, then the screen displays information from the Carbon Black Scan for each snapshot listed.
    • If you select the Show All Images check box, the list might include snapshots that are not compatible and cannot be selected.
    • If no value appears in the Carbon Black Scan (% Complete) column, that indicates that the Carbon Black sensor was not enabled in the Instant Clone golden image when the snapshot was taken. For more information, see the VMware Carbon Black Cloud Documentation.
  5. On the Schedule step, select the Publish Secondary image option.

    To immediately apply the secondary image to selected machines, select the Push to specific machines check box and then select machines from the list.

  6. On the Ready to Complete step, click Finish.

Switching Between the Default and Secondary Image

After you have published the secondary image, options are enabled on the Machines (Instant Clone Details) tab to apply either of the images to selected machines.
  • To apply the secondary image, select the machines on the Machines (Instant Clone Details) page and then select More Commands > Apply Secondary Image.
    Note: The secondary image applies only when the pool is selected for All Machines up-front and not when Machines on Demand is selected.
  • To apply the default image, select the machines on the Machines (Instant Clone Details) page and then select More Commands > Apply Default Image.

Promote or Cancel the Secondary Image

If the new image meets your acceptance criteria, you can promote this secondary image to be your default image. Otherwise, you can cancel the secondary image and the default image will get applied to the desktop pool.
  • There is an option on the Summary tab to promote the secondary image. This causes the secondary image to become the new default image on the pool and applies it to all the machines in the pool. To promote the secondary image, select Maintain > Promote Secondary Image.
  • To cancel the secondary image, select Maintain > Cancel on the Summary tab.
    • If the pool is set to refresh on logoff, the desktops that are currently on the secondary image will revert to the default image once the user logs off.
    • If the pool is not set to refresh on logoff, the desktops on the secondary image remain on it unless a recover, delete, or refresh is performed on the desktop.