Read Before Installing Updating HP-UX 11i v2, September 2004

24
Use the shutdown Command Instead of reboot
Command
In rare cases, the reboot command may hang if a catastrophic
hardware or operating system problem happens during
shutdown.
In previous versions of HP-UX, a timeout and panic occurs if the
system does not completely shutdown after 10 minutes. The
system now waits indefinitely for the shutdown process to
complete.
What to Do
HP recommends you do not use the reboot command. Use the
shutdown command instead.