The clones in an instant-clone desktop pool are based on the same image. When an instant clone is created, the desktop pool are rebalanced across datastores automatically.

An image is a snapshot of a parent VM in vCenter Server. Publishing an image is a process by which internal VMs needed for instant cloning are created. This process only happens once per image and may take some time. Creating an instant-clone desktop pool involves the following operations:

  1. Horizon 7 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 Administrator, 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.


    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.

  2. The clones are created. This process is fast. During this process, the Current Image pane in Horizon Administrator 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.

If you edit a pool to add or remove datastores, rebalancing of the VMs happens automatically when a new clone is created. If you want rebalancing to happen faster, take the following actions:

  • If you remove a datastore, manually remove the desktops on that datastore so that the new desktops are created on the remaining datastores.

  • If you add a datastore, manually remove some desktops from the original datastores so that the new desktops are created on the new datastore. You can also remove all desktops or simply do a push image with the same image so that when the clones are recreated, they are evenly distributed across the datastores.