The stop method for the zone boot component spends 60% of the value for the Stop_timeout performing a complete "zoneadm -z zonename shutdown" for the zone. If that failed, the next 20% of the value for the Stop_timeout will be spent halting the zone performing a "zoneadm —z zonename halt" and perform some additional cleanup steps in order to force the zone into the state installed. Therefore the Stop_timeout value for the zone boot component should be computed so that 60% is enough to successfully shutdown the zone.
The default setting for the Migrationtype variable is cold. For a solaris-kz brand zone, you will be able to set the Migrationtype variable to warm. In such cases, the stop method uses the "zoneadm -z zonename suspend" command instead of the "zoneadm -z zonename shutdown" command. Therefore, the Stop_timeout value must be tuned properly, when the Migrationtype variable to set to warm.