Hitachi HVM Navigator V03-06 User Manual page 261

In order to avoid inadvertent shutdown of HVM during migration of LPARs,
HVM Navigator suppresses the auto shutdown until the migration executed by
Migration functions is complete. By doing so, the HVM remains active even
during any scheduled migration where all LPARs on the HVM become
deactivated (power-off state) to save power or to execute scheduled
maintenance.
Similarly, migration of the last active LPAR does not automatically shut down
the HVM. If shutdown of the HVM is expected, this HVM needs to be manually
shut down after the migration.
Usage notes 5-29
HVM Navigator User's Guide - Migration