In a recomposition, you can provide operating system patches, install or update applications, or modify the virtual machine hardware settings in all the linked clones in a desktop pool.
To recompose linked-clone virtual machines, you update the parent virtual machine in vCenter Server or select a different virtual machine to become the new parent. Next, you take a snapshot of the new parent virtual machine configuration.
You can change the parent virtual machine without affecting the linked clones because they are linked to the replica, not directly to the parent.
You then initiate the recomposition, selecting the snapshot to be used as the new base image for the desktop pool. Horizon Composer creates a new replica, copies the reconfigured OS disk to the linked clones, and anchors the linked clones to the new replica.
The recomposition also refreshes the linked clones, reducing the size of their OS disks.
Desktop recompositions do not affect Horizon Composer persistent disks.
Apply these guidelines to recompositions:
- You can recompose dedicated-assignment and floating-assignment desktop pools.
- You can recompose a desktop pool on demand or as a scheduled event.
You can schedule only one recomposition at a time for a given set of linked clones. Before you can schedule a new recomposition, you must cancel any previously scheduled task or wait until the previous operation is completed. Before you can start a new recomposition immediately, you must cancel any previously scheduled task.
You can schedule multiple recompositions if they affect different linked clones.
- You can recompose selected linked clones or all linked clones in a desktop pool.
- When different linked clones in a desktop pool are derived from different snapshots of the base image or from different base images, the desktop pool includes more than one replica.
- A recomposition can only occur when users are logged off of their linked-clone desktops.
- You cannot recompose linked clones that use one operating system to a new or updated parent virtual machine that uses a different operating system.
- You cannot recompose linked clones to a lower hardware version than their current version. For example, you cannot recompose hardware version 8 clones to a parent virtual machine that is hardware version 7.
- You can set a minimum number of ready, provisioned desktops that remain available for users to connect to during the recompose operation.
