Power policies control how a virtual machine behaves when the associated remote desktop is not in use.

You set power policies when you create or edit a desktop pool. Power Policies describes the available power policies.

Table 1. Power Policies
Power Policy Description
Take no power action Horizon 8 does not enforce any power policy after a user logs off. This setting has two consequences.
  • Horizon 8 does not change the power state of the virtual machine after a user logs off.

    For example, if a user shuts down the virtual machine, the virtual machine remains powered off. If a user logs off without shutting down, the virtual machine remains powered on. When a user reconnects to the desktop, the virtual machine restarts if it was powered off.

  • Horizon 8 does not enforce any power state after an administrative task is completed.

    For example, a user might log off without shutting down. The virtual machine remains powered on. When a scheduled recomposition takes place, the virtual machine is powered off. After the recomposition is completed, Horizon 8 does nothing to change the power state of the virtual machine. It remains powered off.

Always powered on The virtual machine remains powered on, even when it is not in use. If a user shuts down the virtual machine, it immediately restarts. The virtual machine also restarts after an administrative task such as refresh, recompose, or rebalance is completed.

Select Always powered on if you run batch processes or system management tools that must contact the virtual machines at scheduled times.

Suspend The virtual machine enters a suspended state when a user logs off, but not when a user disconnects.

You can also configure machines in a dedicated pool to be suspended when a user disconnects without logging off. To configure this policy, you must set an attribute in Horizon Directory. See Configure Dedicated Machines To Be Suspended After Users Disconnect.

When multiple virtual machines are resumed from a suspended state, some virtual machines might have delays in powering on. Whether any delays occur depends on the ESXi host hardware and the number of virtual machines that are configured on an ESXi host. Users connecting to their desktops from Horizon Client might temporarily see a desktop-not-available message. To access their desktops, users can connect again.

This policy is not available for dedicated instant-clone desktop pools created with NVIDIA GRID vGPU.
Power off The virtual machine shuts down when a user logs off, but not when a user disconnects.

This policy is not available for dedicated instant-clone desktop pools created with NVIDIA GRID vGPU.

When you configure a full-clone desktop pool with floating assignments, the machine is not powered off even with the power policy set to Power off when the maximum number of machines is equal to the number of spare (power on) machines.

Note: When you add a machine to a manual desktop pool, verify that the machine is powered on to ensure that it is fully configured, even when you select the Power off or Take no power action power policies. After Horizon Agent is configured, it is marked as Ready, and the normal power-management settings for the pool apply.

For manual desktop pools that contain vSphere virtual machines, a spare machine is always powered on so that users can connect to it. The spare machine is powered on no matter which power policy is in effect.

When Horizon 8 Applies the Power Policy describes when Horizon 8 applies the configured power policy to full-clone desktop pools.

Table 2. When Horizon 8 Applies the Power Policy
Desktop Pool Type The power policy is applied ...
Instant-clone desktop pool with dedicated assignment

Instant-clone desktop pool that contains vSphere virtual machines with dedicated assignment

 To dedicated virtual machines configured with default power policy set to Always powered on.

On assigned machines, power operations are initiated by session management. Virtual machines are powered on when a user requests an assigned machine and are powered off or suspended when the user logs off.

Note: The Always powered on policy applies to assigned and unassigned machines.
Automated full-clone pool with dedicated assignment

Manual desktop pool that contains vSphere virtual machines with dedicated assignment

To unassigned machines only.

On assigned machines, power operations are initiated by session management. Virtual machines are powered on when a user requests an assigned machine and are powered off or suspended when the user logs off.

Note: The Always powered on policy applies to assigned and unassigned machines.
Automated full-clone pool with floating assignment

Manual desktop pool that contains vSphere virtual machines with floating assignment

 When a machine is not in use and after a user logs off.

When you configure the Power off or Suspend power policy for a floating-assignment desktop pool, set Automatically logoff after disconnect to Immediately to prevent discarded or orphaned sessions.

Manual desktop pool that contains one vSphere virtual machine with floating or dedicated assignment.

Power operations are initiated by session management. The virtual machine is powered on when a user requests an assigned machine and is powered off or suspended when the user logs off.

Note: The Always powered on policy applies to assigned and unassigned machines.

How Horizon 8 applies the configured power policy to automated pools depends on whether a machine is available. See How Power Policies Affect Automated Desktop Pools for more information.