Select the power off option for the managed system

Allows you to control how the managed system is powered off during a disruptive install and activate update.

Power off automatically (shortest overall update time)
Allows the HMC to control when the power off occurs, when necessary, and ensures the shortest update lapsed time.
Delay power off with confirmation (shortest system down time)
Allows you to control when the power off occurs and ensures the shortest system down time. You can delay powering off the managed system and control when you want to quiesce, or close, applications running on the system.