HP-UX Virtual Partitions Administrator's Guide (includes A.05.02)

Monitor and Shell Commands
Shutting Down or Rebooting a Virtual Partition
Chapter 5
161
When to Shutdown All Virtual Partitions
The only times you need to shutdown all the virtual partitions within a hard partition are when:
a hardware problem or nPartition modification requires the nPartition to be down. Note that PCI OL* is
supported on vPars A.03.xx and A.04.
the entire hard partition hangs. This might be a problem with the Monitor.
you need to update the vPars Monitor (/stand/vpmon)