The following steps outline how to recompose a linked clone desktop pool using the Horizon Administrator console:
- Log in to the Horizon Administrator console using an AD account that has administrative permissions within Horizon.
- Go to Catalog and open the Desktop Pools window within the console.
- In the Desktop Pools window, click on the linked clone pool you wish to recompose. In our example, we will click on the pool called AppVolumes-W10 to open the AppVolumes-W10 window.
- On the right-hand side of the AppVolumes-W10 window, open the View Composer drop-down menu and click on Recompose to open the Recompose window.
- On the Image page of the Recompose window (shown in the following screenshot), highlight the updated snapshot that you wish to use with your desktops. You may also select a different parent VM and accompanying snapshot by clicking on the Change... button, as long as they use the same OS as the existing desktops. In our example, we have chosen a new snapshot of the existing parent VM. Click on Next to move to the next step:
By default, Horizon will use the selected snapshot when deploying new desktops within the desktop pool. Uncheck the Change the default image for new desktops checkbox to change this behavior and force new desktops to use the existing image.
- On the Scheduling page of the Recompose window, select the desired scheduling options and click on Next. These are the same scheduling options that appear when performing a desktop refresh.
- Review the options in the Ready to Complete page of the Recompose window. If changes are required, click on the Back button to return to the previous screen. Click on Finish to begin or schedule the recompose operation, depending on what was configured in the previous step.
The time required to complete a linked clone desktop recompose operation varies based on a number of different factors beyond that of the Horizon configuration itself. Generally speaking, under average circumstances, it will take no more than 15 minutes per desktop, starting from the time that Horizon Composer performs the initial powerdown of the desktop.
If a desktop pool is configured to use Windows Sysprep for machine customization, a new Windows Machine System Identifier (SID) will be generated during a recompose operation. Consider any potential issues this may cause within your environment. The only alternative is to redeploy the desktops using VMware QuickPrep instead of Windows Sysprep. For more information about the differences between QuickPrep and System, consult the Choosing QuickPrep or Sysprep to Customize Linked-Clone Machines section of the VMware document, Setting Up Published Desktops and Applications in View (https://docs.vmware.com/en/VMware-Horizon-7/index.html).
The status of the recompose operation can be viewed in the Tasks tab of the desktop pool window.