JJC Systems
Recomposing Horizon Desktop Pool
Objective: The objective of this Standard Operating Procedure (SOP) is to provide a step-by-step guide for recomposing a Horizon Desktop Pool. Recomposing the pool involves updating the base image and distributing the updated image to the virtual desktops within the pool. This process ensures that users have access to the latest software updates, configurations, and applications.
Requirements:
Administrator access to the Horizon infrastructure
Access to the updated base image
Active Horizon Desktop Pool
Note: It is recommended to perform this procedure during off-peak hours to minimize user disruption.
Procedure:
1. Preparation:
Notify users: Inform the users in the affected desktop pool about the upcoming recomposition. Advise them to save their work and log off before the scheduled maintenance.
Verify base image: Ensure that the updated base image is prepared and available in a suitable location accessible to the Horizon infrastructure.
2. Disable provisioning:
Open the Horizon Administrator Console.
Navigate to "Inventory">"Pools" and select the target desktop pool.
In the "Summary" tab, click "Edit."
Under the "Provisioning Settings" section, set the "Provisioning Enabled" option to "No."
Click"OK"to save the changes.
3. Prepare the updated base image:
Power on a virtual machine with the latest base image.
Install any necessary updates, applications, or configurations.
Perform a thorough testing and validation of the updated base image to ensure stability and compatibility with the target pool.
Shutdown the virtual machine.
4. Take a snapshot of the updated base image:
Open the vSphere Client or the appropriate hypervisor management tool.
Locate the virtual machine running the updated base image.
Right-click on the virtual machine and select "Snapshot" > "Take Snapshot."
Provide a descriptive name for the snapshot (e.g.,"Pool Recomposition - <date>").
Ensure that the snapshot is successfully created.
5. Initiate recomposition:
Return to the Horizon Administrator Console.
Navigate to"Inventory"> "Pools"and select the target desktop pool.
In the "Summary" tab, click "Recompose."
Select the updated base image snapshot created in Step 4.
Review the recomposition details and ensure they are accurate.
Click "Next" to start the recomposition process.
Monitor the progress of the recomposition task. It may take some time depending on the size of the pool and the number of virtual desktops.
6. Verify recomposition completion:
Once the recomposition process is finished, review the task status in the Horizon Administrator Console to ensure that it completed without errors.
Power on a sample of virtual desktops within the pool to validate the new base image deployment.
Verify that the updated software, configurations, and applications are present on the virtual desktops.
Test essential functions and applications to confirm their proper functionality.
7. Re-enable provisioning:
Open the Horizon Administrator Console.
Navigate to "Inventory" > "Pools" and select the target desktop pool.
In the "Summary" tab, click "Edit."
Under the "Provisioning Settings", set the "Provisioning Enabled"option to "Yes."
Click "OK" to save the changes.
8. Notify users:
Inform the users that the recomposition process has been completed successfully.
Advise them to log in and resume their work.
9. Documentation:
Update the appropriate documentation to reflect the changes made to the desktop pool and the base image.

Note: It is crucial to thoroughly test the updated base image and perform a pilot deployment to a subset of virtual desktops before proceeding with a full-scale recomposition to minimize potential issues and user disruptions. This concludes the Standard Operating Procedure for recomposing a Horizon Desktop Pool.