HP-UX System Administrator's Guide: Overview

Example 3-4 Run Level Transition Examples
The following two examples show what happens during two typical situations:
Transition up
The file /etc/inittab contains an entry telling init that
the initial run level for the system during boot-up should be
run level 3:
init:3:initdefault:
To reach run level 3, the system transitions:
• From run level 0 (the halted state)
• to run level 1 (running scripts pointed to by links in the
/sbin/rc1.d directory whose names begin with the
letter S — for example, /sbin/rc1.d/
S100localmount, /sbin/rc1.d/S520syncer, and
others).
• to run level 2 (running scripts pointed to by links in the
/sbin/rc2.d directory whose names begin with the
letter S — for example, /sbin/rc2.d/S500inetd,
/sbin/rc2.d/S900samba, and others).
• and finally to run level 3 (running scripts pointed to by
links in the /sbin/rc3.d directory whose names begin
with the letter S — for example, /sbin/rc3.d/
S823hpws_webmin, /sbin/rc3.d/
S823hpws_webproxy, and others).
Transition down If HP-UX is currently in run level 3 and an system
administrator with appropriate privileges executes the
command:
/sbin/init 1
The system will transition:
• From run level 3
• to run level 2 (running scripts pointed to by links in the
/sbin/rc2.d directory whose names begin with the
letter K — for example, /sbin/rc2.d/
K177hpws_tomcat, and others).
• and finally to run level 1 (running scripts pointed to by
links in the /sbin/rc1.d directory whose names begin
with the letter K — for example, /sbin/rc1.d/
K500inetd, and others).
Commands for Manipulating System Run Levels
The following commands can be used to set, change, and view HP-UX run levels:
Start-up and Shutdown 91