Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 267 — #293

The SUSE LINUX Boot Concept

To change runlevels while the system is running, enter init and the cor-

responding number as an argument. Only the system administrator is al-

lowed to do this. init 1 (or shutdown now) causes the system to change

to single user mode, which is used for system maintenance and administra-

tion. After ﬁnishing his work, the administrator can switch back to the nor-

mal runlevel by entering init 3, which starts all the essential programs

and allows regular users to log in and to work with the system. init 0 (or

shutdown -h now) causes the system to halt. init 6 (or shutdown -r

now) causes it to shut down with a subsequent reboot.

Note

Runlevel 2 with a /usr/ Partition Mounted via NFS

You should not use runlevel 2 if your system mounts the /usr/

partition via NFS. The /usr/ directory holds important pro-

grams essential for the proper functioning of the system. Because

the NFS service is not made available by runlevel 2 (local mul-

tiuser mode without remote network), the system would be

seriously restricted in many aspects.

Note

Table 11.1: Available Runlevels

Runlevel Description

0 System halt

S Single user mode; from the boot prompt, only with US

keyboard

1 Single user mode

2 Local multiuser mode without remote network (e.g., NFS)

3 Full multiuser mode with network

4 Not used

5 Full multiuser mode with network and X display man-

ager — KDM (default), GDM, or XDM

6 System reboot

Runlevel 5 is the default runlevel in all SUSE LINUX standard installations.

Users are prompted for login directly under a graphical interface. However,

if the default runlevel is 3 and you want to change it to 5, you ﬁrst need

to conﬁgure the X Window System in the required way (see Chapter 12 on

267SUSE LINUX Enterprise Server