If a failure is detected after upgrading or if the application is not compatible with an upgraded component, you can fall back to the original boot environment with the luactivate command.
When you have migrated to a ZFS root pool from a UFS boot environment and you then decide to fall back to the UFS boot environment, you again need to import any ZFS storage pools that were created in the ZFS boot environment. These ZFS storage pools are not automatically available in the UFS boot environment. You will see messages similar to the following example when you switch back to the UFS boot environment.
# luactivate c0t0d0 WARNING: The following files have changed on both the current boot environment <new-ZFSbe> zone <global> and the boot environment to be activated <c0t0d0>: /etc/zfs/zpool.cache INFORMATION: The files listed above are in conflict between the current boot environment <ZFSbe> zone <global> and the boot environment to be activated <c0t0d0>. These files will not be automatically synchronized from the current boot environment <new-ZFSbe> when boot environment <c0t0d0>
For examples of falling back to the original boot environment, see Chapter 6, Failure Recovery: Falling Back to the Original Boot Environment (Tasks).