HP-UX System Administrator's Guide: Overview

the boot process. They also locate and initialize communications with console
display and keyboard devices, and a boot device.
2. Pre-boot firmware/software routines then load and execute the HP-UX boot loader.
3. The HP-UX boot loader:
— Locates, opens, and reads the kernel file and copies the kernel into memory
— Initiates the HP-UX kernel
4. HP-UX goes through its initialization process and begins normal operation.
For complete details on the HP-UX boot process and its possible variations, see HP-UX
System Administrator’s Guide: Routine Management Tasks.
Stopping (Shutting Down) HP-UX
“READY . . . SET . . . GO!” As with the famous phrase, there is a definite order that you
should follow to shut down your system—or you may encounter problems.
When shutting down an HP-UX system:
1. First, notify everyone who is likely to be affected by the shutdown, giving them a
chance to complete work in progress, and if necessary unmount file systems that
were NFS-mounted from your system.
2. Then, shutdown any programs you might be running that would not be safely
shutdown by one of the system’s kill scripts (“Startup and Kill Scripts (Run Level
Transitions)”).
3. Finally, use the shutdown command to shut down the system. The shutdown
command:
a. allows you to notify the users of the system of the shutdown in progress if you
have not previously done so, or to remind those users that the shutdown is
imminent.
b. transitions backward through the run levels (executing the kill links in the
directories /sbin/rc[0-4].d)
c. and finally calls reboot to perform a sync operation that insures memory
structures are written to disk before memory is overwritten by the subsequent
boot.
For details on the HP-UX shut down process, see HP-UX System Administrator’s Guide:
Routine Management Tasks.
Abnormal Shutdowns (System Crashes)
When your system crashes, it is important to know why so that you can take actions
to prevent it from happening again. Sometimes, it is easy to determine why: for example,
if somebody trips over the cable connecting your computer to the disk containing your
root file system (disconnecting the disk).
Start-up and Shutdown 93