The power management function enables you to control the power state of the physical machines and the online virtual machines in your organization. The primary reasons for using power management are to:
•Prepare your machines for maintenance tasks
•Reduce power consumption and noise
•Reduce operating costs
•Prolong battery life
You can shut down, restart, or wake up machines either immediately or on a scheduled basis. You also have the ability to put machines into a sleep or hibernate state.
TIP: If you want to perform power tasks on offline virtual machines that reside on an ESXi Hypervisor, you can do so using the Virtual Inventory feature.
For information on how to perform power management tasks, see:
Extremely Flexible Implementation Options
Security Controls provides a number of ways for you to implement the power management options.
•Immediate Shutdowns or Restarts With No User Warning:You can immediately shut down or restart one or more connected machines from Machine View or Scan View by using a right-click command. The machines must be in a fully powered on state in order to accept the shutdown or restart command. These immediate actions will typically be used for maintenance purposes when you cannot wait for machines to be shut down or restarted. When performing an immediate restart of a machine it will always be returned to a fully powered on state. For more information, see Shutdown Implementation Notes and Restart Implementation Notes.
•Scheduled Shutdowns or Restarts With A User Warning: You can shut down or restart one or more connected machines by using a power state template. The advantage of using a power state template is that it gives you the option to provide a warning to any active users of the machines. It also enables you to schedule the action to happen immediately or at some time in the future.
Scheduled shutdowns and restarts are typically used for reducing power or turning off machines at night, over weekends, or on holidays. This can be used to fulfill a corporate "green" initiative by saving power when machines are not being used. The machines must initially be in a fully powered on state in order for the scheduled job to be performed.
•Initiate sleep or hibernate state with or without a prior restart: A power state template can be used to put machines into a sleep state or a hibernate state. You can choose to perform the action with or without a prior restart of the target machines. As with all jobs initiated using a power state template, you can schedule the job to run now or at some time in the future. For more information, see Sleep and Hibernation Implementation Notes.
•Immediate or scheduled Wake-on-LAN: The Wake-on-LAN (WoL) feature is used to return machines to a fully powered on state. This is performed from Machine View or Scan View by using a right-click command. Any connected machine that is sleeping, hibernating, or powered off (but with power available to the network card) can be awakened by a WoL request. One typical reason for using WoL is to turn on machines that have been powered off overnight or over a long holiday weekend, making the machines ready for use for the coming work day. Another reason may be to power on machines prior to performing maintenance tasks such as console-based patch or asset scans. Machines that are sleeping, hibernating, or powered off cannot be scanned, so using the WoL feature ensures that your maintenance tasks will be performed on schedule.
The Wake-on-LAN request can be issued immediately, or it can be scheduled to occur at a specific time. It's like scheduling a wakeup call for each machine. For more information on WoL, see Wake-on-LAN Implementation Notes.
Machines that are sleeping, hibernating, or powered off cannot be restarted or awakened using a power state template, they must be awakened using the WoL feature.
Agentless vs. Agent-based
Power management tasks can be performed using either an agentless or an agent-based method. This section describes the agentless method. For information on performing agent-based power tasks, see Creating and Configuring a Power Task.
An agentless power state task will push a small number of files from the console to each target machine. If a large number of machines are involved it may affect the performance of your network.