With the maintenance operation, you can schedule recurring or immediate maintenance of all the RDS hosts in an automated instant-clone farm. During each maintenance cycle, all the RDS hosts are refreshed from the golden image virtual machine. Depending on how you want the golden image to be managed, you can change the golden image and snapshot source in your pool from vCenter to Image Catalog or reverse. For more information on the Image Management Service, see the Managing Horizon Images from the Cloud document.

You can make changes to the golden image virtual machine without affecting the RDS host instant clones because the snapshot of the current golden image VM is used for maintenance. The instant clones created in the automated farm use the information in the golden image VM for their system configuration.

If possible, schedule maintenance operations during off-peak hours to ensure all that RDS hosts have finished maintenance and are available during peak hours.


  • Decide when to schedule the maintenance operation. By default, Connection Server starts the operation immediately.

    You can schedule an immediate maintenance or recurring maintenance or both for a farm. You can schedule maintenance operations on multiple farms concurrently.

  • Decide whether to force all users to log off when the maintenance operation begins or wait for each user to log off before refreshing that user's machine.

    If you force users to log off, Horizon 8 notifies users before they are disconnected and allows them to close their applications and log off.

  • Decide the minimum farm size. The minimum farm size is the number of RDS hosts that are kept available at all times to allow users to continue to use the farm. For example, if the farm size is ten and the minimum farm size is two, then maintenance will be performed on eight RDS hosts. As each RDS host becomes available again then the remaining hosts will go through maintenance. All RDS hosts are managed individually, so as one host becomes available then one of the remaining hosts will be put into maintenance.

    However, if you schedule immediate maintenance, then all the RDS hosts in the farm will be put into maintenance.

    All RDS hosts will also be subject to policy and will wait for logoff or force users to logoff depending upon what policy is configured.

  • Decide whether to stop provisioning at first error. If you select this option and an error occurs when Connection Server provisions an instant-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 an instant-clone, other clones continue to be provisioned and customized.

  • Verify that provisioning is enabled. When provisioning is disabled, Horizon 8 stops the machines from being customized after they are refreshed.
  • If your deployment includes replicated Connection Server instances, verify that all instances are the same version.


  1. In Horizon Console, select Inventory > Farms.
  2. Click the pool ID of the farm for which you want to schedule a maintenance.
  3. Click Maintain > Schedule.
  4. In the Schedule Recurring Maintenance wizard, choose a maintenance mode.
    • Option Action
      Recurring Schedules periodic maintenance of all the RDS host servers in a farm.
      • Select a date and time from which the maintenance is effective.
      • Select a maintenance period. You can select daily, monthly, or weekly maintenance periods.
      • Select a repeat interval in days for the maintenance operation to recur.

      If an immediate maintenance is scheduled on a farm, then the immediate maintenance date becomes the effective date for any recurring maintenance. If you cancel the immediate maintenance, then the current date becomes the effective date for recurring maintenance.

      Immediate Schedules immediate maintenance of all the RDS host servers in a farm. Immediate maintenance creates a one-time maintenance schedule for immediate or near future maintenance. Use immediate maintenance to refresh the farm from a new image when you want to apply urgent security patches.
      Select an immediate maintenance configuration.
      • Select Start Now to start the maintenance operation instantly.
      • Select Start at to start the maintenance operation at a near future date and time. Enter the date and Web browser local time.
      Note: Recurring maintenance will be put on hold until immediate maintenance is complete.
      Publish Secondary Image

      The image you used to create a pool is the default image. By default, all maintenance operations use this image to update all machines in the farm.

      You can optionally publish a secondary image, which you can use to update a subset of the machines in the farm while leaving the rest unchanged.

      After you have published the secondary image, options are enabled to apply either of the images to selected machines without using the Schedule Recurring Maintenance process.
      • To apply the secondary image, select the machines on the RDS Hosts tab of the Farms page and then select More Commands > Apply Secondary Image.
      • To apply the default image, select the machines on the RDS Hosts tab of the Farms page and then select More Commands > Apply Default Image.
      If the new image meets your acceptance criteria, you can promote this secondary image to be your default image. Otherwise, you can cancel the secondary image and the default image will get applied to the desktop pool.
      • There is an option on the Summary tab to promote the secondary image. This causes the secondary image to become the new default image on the pool and applies it to all the machines in the pool. To promote the secondary image, select Maintain > Promote Secondary Image.
      • To cancel the secondary image, select Maintain > Cancel on the Summary tab.
        • If the pool is set to refresh on logoff, the desktops that are currently on the secondary image will revert to the default image once the user logs off.
        • If the pool is not set to refresh on logoff, the desktops on the secondary image remain on it unless a recover, delete, or refresh is performed on the desktop.
  5. Click Next.
  6. (Optional) Click Change to change the golden image virtual machine. You can change the image source from vCenter to Image Catalog or vice versa.
  7. Select a snapshot.
    You cannot select a different snapshot unless you clear the Use current parent VM image checkbox. Click Snapshot Details to display details about the snapshot. If the image source is Image Catalog, select the required stream and marker.
    Note: If you are a VMware Carbon Black customer and select a golden image configured with Carbon Black, then the screen displays information from the Carbon Black Scan for each snapshot listed.
    • If you select the Show All Images check box, the list might include snapshots that are not compatible and cannot be selected.
    • If no value appears in the Carbon Black Scan (% Complete) column, that indicates that the Carbon Black sensor was not enabled in the Instant Clone golden image when the snapshot was taken. For more information, see the VMware Carbon Black Cloud Documentation.
  8. Click Next.
  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. Click Finish.