Upgrading with Solaris Live Upgrade enables a duplicate boot environment to be upgraded while the active boot environment is still running, thus eliminating downtime of the production environment. Solaris Live Upgrade can be run with a GUI or CLI. You first create a duplicate boot environment. After a duplicate boot environment is created, you can upgrade or install a Solaris Flash archive on the inactive boot environment. When you are ready, you activate the inactive boot environment and at the next reboot, the inactive boot environment is switched to become the active boot environment. If a failure occurs, you can recover your original boot environment with a simple activate and reboot.
For a detailed overview and instructions, refer to Chapter 29, Solaris Live Upgrade (Topics).