Publishing an image is a process by which internal VMs needed for instant cloning are created from a golden image and its snapshot. This process only happens once per image and may take some time.

Horizon performs the following steps to create a pool of instant clones:

  1. Horizon publishes the image that you select. In vCenter Server, four folders (ClonePrepInternalTemplateFolder, ClonePrepParentVmFolder, ClonePrepReplicaVmFolder, and ClonePrepResyncVmFolder) are created if they do not exist, and some internal VMs that are required for cloning are created. In Horizon Console, you can see the progress of this operation on the Summary tab of the desktop pool. During publishing, the Pending Image pane shows the name and state of the image.
    Note: Do not tamper with the four folders or the internal VMs that they contain. Otherwise, errors might occur. The internal VMs are removed when they are no longer needed. Normally the VMs are removed within 5 minutes of pool deletion or a push-image operation. However, sometimes the removal can take up to 30 minutes. If there are no internal VMs in all four folders, these folders are unprotected and you can delete these folders.
  2. After the image is published, Horizon creates the instant clones.. This process is fast. During this process, the Current Image pane in Horizon Console shows the name and state of the image.

After the pool is created, you can change the image through the push-image operation. As with the creation of a pool, the new image is first published. Then the clones are recreated.

When an instant clone pool is created, Horizon spreads the pool across datastores automatically in a balanced way. If you edit a pool to add or remove datastores, rebalancing of the cloned desktops happens automatically when a new clone is created.