Evacuation is the process of live migrating all the running kernel zones off a system at once, and optionally returning them to the system later. A primary use for evacuation is zero-downtime system maintenance. By live migrating all kernel zones from a host system onto other systems temporarily, you can perform maintenance on the host system without having to take down hosted applications that are running in those kernel zones. You can optionally evacuate all zones, including kernel zones and native solaris zones that are not running and are in the INSTALLED state.
See Chapter 6, Evacuating Oracle Solaris Kernel Zones to a Target Host in Creating and Using Oracle Solaris Kernel Zones for more information.