With the View Composer recompose operation, you can update the machine image of all the RDS hosts in an automated linked-clone farm. You can update the hardware settings or the software of the parent virtual machine and run the recompose operation to have the changes propagated to all the RDS hosts in the farm.

You can make changes to the parent virtual machine without affecting the RDS host linked clones because the clones are linked to a replica of the parent. The recompose operation deletes the old replica and creates a new one for the clones to link to. The recompose creates new linked clones, which typically use less storage because the disk files of linked clones usually grow in size over time.

You can recompose an automated farm but not individual RDS hosts in the farm. You cannot recompose linked clones to a lower hardware version than their current hardware version.

If possible, schedule recompose operations during off-peak hours because the operation can be time consuming.

Prerequisites

  • Verify that you have a snapshot of a parent virtual machine. You must specify a snapshot when you recompose. The snapshot can be on the current parent virtual machine or a different one.
  • Decide when to schedule the recompose operation. By default, View Composer starts the operation immediately.

    You can schedule only one recompose operation at a time for a farm. You can recompose multiple farms concurrently.

  • Decide whether to force all users to log off as soon as the recompose operation begins or wait for each user to log off before recomposing that user's machine.

    If you force users to log off, Horizon 7 notifies users before they are disconnected and allows them to close their applications and log off.

  • Decide whether to stop provisioning at first error. If you select this option and an error occurs when View Composer provisions a linked clone, provisioning stops. You can select this option to ensure that resources such as storage are not consumed unnecessarily.

    Selecting the Stop at first error option does not affect customization. If a customization error occurs on a linked clone, other clones continue to be provisioned and customized.

  • Verify that provisioning is enabled. When provisioning is disabled, Horizon 7 stops the machines from being customized after they are recomposed.
  • If your deployment includes replicated Connection Server instances, verify that all instances are the same version.

Procedure

  1. In Horizon Administrator, select Resources > Farms.
  2. Double-click the pool ID of the farm that you want to recompose.
  3. Click Recompose.
  4. (Optional) Click Change to change the parent virtual machine.
    The new parent virtual machine must run the same version of the operating system as the current parent virtual machine.
  5. Select a snapshot.
  6. (Optional) Click Snapshot Details to display details about the snapshot.
  7. Click Next.
  8. (Optional) Schedule a start time.
    The current time is filled in by default.
  9. (Optional) Specify whether to force users to log off or wait for users to log off.
    The option to force users to log off is selected by default.
  10. (Optional) Specify whether to stop provisioning at first error.
    This option is selected by default.
  11. Click Next.
    The Ready to Complete page is displayed.
  12. (Optional) Click Show Details to display details of the recompose operation.
  13. Click Finish.

Results

In vCenter Server, you can monitor the progress of the recompose operation on the linked-clone virtual machines.

Note: During the recompose operation, View Composer runs Sysprep again on the linked clones. New SIDs and third-party GUIDs might be generated for the recomposed virtual machines. For details, see "Recomposing Linked Clones Customized with Sysprep" in the Setting Up Virtual Desktops in Horizon 7 document.