You can perform maintenance on hosts where instant clones reside by putting the ESXi hosts into maintenance mode. You can use the vSphere Web Client to put the ESXi host into maintenance mode.

In most cases, using instant clones does not change your operational flow of how you perform ESXi host maintenance tasks. Horizon will automatically delete the instant clone parentVMs to alllow the ESXi host to go into maintenance mode. When you use VMware Update Manager, an extra step is required.

If you use VMware Update Manager to update your ESXi hosts, you must delete or disable the instant clone parentVM before VMware Update Manager can successfully update the ESXi hosts. If you use an older version of Horizon, you must manually delete the instant clone parentVM on all the ESXi hosts by using the instant-clone utilities. To use the instant-clone utilities, see Instant-Clone Maintenance Utilities.

Starting with Horizon version 2006, you can globally disable all of the instant clone parentVMs in a vCenter so that VMware Update Manager can update the ESXi hosts in that vCenter. If you disable parentVM setting for a vCenter, Horizon will automatically delete all the parentVMs on every single host in that vCenter, so that the hosts can go into maintenance mode without any manual intervention. Deleting the parentVM does not impact the operations of instant clones as Horizon can create instant clones with or without parentVMs.

To selectively disable parentVMs for certain clusters only rather than the entire vCenter, see the KB article 80369. If you leave the parentVM setting for the vCenter disabled, any new instant clones are then provisioned without parentVMs. If you want Horizon to use parentVMs when creating instant clones, then you can re-enable the parentVM setting for the vCenter after VMware Update Manager completes host maintenance. You must disable the parentVM for the vCenter before every update event.
Note: If you use VMware Update Manager, keep the instant clone parentVMs disabled for your vCenter to simplify your ESXi maintenance.


  1. In Horizon Console, select Settings > Servers.
  2. Select the server from the list, click More and select Disable ParentVMs.
  3. Log in to vSphere Web Client.
  4. Select the ESXi host that you want to put into maintenance and click Maintenance Mode > Enter Maintenance Mode.