The first time you boot from a newly created boot environment, Solaris Live Upgrade synchronizes the new boot environment with the boot environment that was last active. After this initial boot and synchronization, Solaris Live Upgrade does not perform a synchronization unless requested. To force a synchronization, you use the luactivate command with the -s option.
You might want to force a synchronization if you are maintaining multiple versions of the Solaris OS. You might want changes in files such as email or passwd/group to be in the boot environment you are activating to. If you force a synchronization, Solaris Live Upgrade checks for conflicts between files that are subject to synchronization. When the new boot environment is booted and a conflict is detected, a warning is issued and the files are not synchronized. Activation can be completed successfully, despite such a conflict. A conflict can occur if you make changes to the same file on both the new boot environment and the active boot environment. For example, you make changes to the /etc/passwd file on the original boot environment. Then you make other changes to /etc/passwd file on the new boot environment. The synchronization process cannot choose which file to copy for the synchronization.
Use this option with great care, because you might not be aware of or in control of changes that might have occurred in the last-active boot environment. For example, if you were running Solaris Express 5/07 software on your current boot environment and booted back to a Solaris 9 release with a forced synchronization, files could be changed on the Solaris 9 release. Because files are dependent on the release of the OS, the boot to the Solaris 9 release could fail because the Solaris Express 5/07 files might not be compatible with the Solaris 9 files.