From foogazi.com
If you don’t already know, a runlevel is what Linux uses as a mode of operation. A ‘runlevel’ defines the state of the operating system after power on.
Typically, Linux runlevels look like the following:
0 – Halt (shutdown)
1 – Single-User mode
2-5 – Full multi-user mode with console logins and display manager if it’s installed
6 – Reboot
On most Linux servers, the default runlevel will be set to runlevel 3. Multi-user mode and console logins only. Whereas, most Linux desktops, the default runlevel will be set to runlevel 5.
If you want to boot into a specific runlevel every time your computer turns on, all you need to do is edit the /etc/inittab. For this example, we will change the runlevel from 3 to 5.
# vi /etc/inittab
Modify the line that looks like this:
id:3:initdefault:
And change the number 3, to 5.
id:5:initdefault:
Save the file. Next time you reboot Linux will boot directly into your desktop window manager.
if you want to see what the current runlevel settings are, on ubuntu, simply run;
root@host:~$ chkconfig
NetworkManager.dpkg-backup off
acpi-support 2345
acpid off
alsa-mixer-save off
alsasound off
anacron off
apmd on
apparmor on
apport off
atd off
auditd 0S
avahi-daemon off
binfmt-support on
bluetooth on
bootlogd off
On a Redhat/CentOS box, the chkconfig command alone will give you parameters to set in order to view the results;
[root@host.myserver.com] ~ >> chkconfig
chkconfig version 1.3.30.2 - Copyright (C) 1997-2000 Red Hat, Inc.
This may be freely redistributed under the terms of the GNU Public License.
usage: chkconfig --list [name]
chkconfig --add
chkconfig --del
chkconfig [--level
To see a comprehensive list of current runlevel settings, use the –list flag
[root@host.myserver.com] ~ >> chkconfig --list
acpid 0:off 1:off 2:off 3:off 4:off 5:off 6:off
anacron 0:off 1:off 2:off 3:off 4:off 5:off 6:off
apf 0:off 1:off 2:on 3:on 4:on 5:on 6:off
atd 0:off 1:off 2:off 3:on 4:on 5:on 6:off
auditd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
autofs 0:off 1:off 2:off 3:on 4:on 5:on 6:off
avahi-daemon 0:off 1:off 2:off 3:off 4:off 5:off 6:off
avahi-dnsconfd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
bandmin 0:off 1:off 2:on 3:on 4:on 5:on 6:off
conman 0:off 1:off 2:off 3:off 4:off 5:off 6:off
courier-authlib 0:off 1:off 2:on 3:on 4:on 5:on 6:off
courier-imap 0:off 1:off 2:on 3:on 4:on 5:on 6:off
cpanel 0:off 1:off 2:off 3:on 4:on 5:on 6:off
cpuspeed 0:off 1:on 2:off 3:off 4:off 5:off 6:off
crond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
dnsmasq 0:off 1:off 2:off 3:off 4:off 5:off 6:off
exim 0:off 1:off 2:on 3:on 4:on 5:on 6:off
fastmail 0:off 1:off 2:on 3:on 4:on 5:on 6:off
filelimits 0:off 1:off 2:on 3:on 4:on 5:on 6:off
firstboot 0:off 1:off 2:off 3:on 4:off 5:on 6:off
haldaemon 0:off 1:off 2:off 3:off 4:off 5:off 6:off
httpd 0:off 1:off 2:off 3:on 4:off 5:on 6:off
ip6tables 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ipaliases 0:off 1:off 2:on 3:on 4:on 5:on 6:off
iptables 0:off 1:off 2:off 3:off 4:off 5:off 6:off
irda 0:off 1:off 2:off 3:off 4:off 5:off 6:off
irqbalance 0:off 1:off 2:on 3:on 4:on 5:on 6:off
kudzu 0:off 1:off 2:off 3:off 4:off 5:off 6:off
lvm2-monitor 0:off 1:on 2:on 3:on 4:on 5:on 6:off
mcstrans 0:off 1:off 2:off 3:off 4:off 5:off 6:off
mdmonitor 0:off 1:off 2:off 3:off 4:off 5:off 6:off
mdmpd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
messagebus 0:off 1:off 2:off 3:off 4:off 5:off 6:off
microcode_ctl 0:off 1:off 2:on 3:on 4:on 5:on 6:off
multipathd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
mysql 0:off 1:off 2:on 3:on 4:on 5:on 6:off
named 0:off 1:off 2:on 3:on 4:on 5:on 6:off
netconsole 0:off 1:off 2:off 3:off 4:off 5:off 6:off
netfs 0:off 1:off 2:off 3:on 4:on 5:on 6:off
netplugd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
netprep 0:off 1:off 2:on 3:on 4:on 5:on 6:off
network 0:off 1:off 2:on 3:on 4:on 5:on 6:off
nfs 0:off 1:off 2:off 3:off 4:off 5:off 6:off
nfslock 0:off 1:off 2:off 3:off 4:off 5:off 6:off
nscd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
ntpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
oddjobd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
pcscd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
psacct 0:off 1:off 2:off 3:off 4:off 5:off 6:off
pure-ftpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
rawdevices 0:off 1:off 2:off 3:on 4:on 5:on 6:off
rdisc 0:off 1:off 2:off 3:off 4:off 5:off 6:off
readahead_early 0:off 1:off 2:off 3:off 4:off 5:off 6:off
readahead_later 0:off 1:off 2:off 3:off 4:off 5:off 6:off
restorecond 0:off 1:off 2:on 3:on 4:on 5:on 6:off
ror 0:off 1:off 2:on 3:on 4:on 5:on 6:off
rpcgssd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rpcidmapd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
rpcsvcgssd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
saslauthd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
securetmp 0:off 1:off 2:on 3:on 4:on 5:on 6:off
smartd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
sonarpush 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sshd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
syslog 0:off 1:off 2:on 3:on 4:on 5:on 6:off
sysstat 0:off 1:off 2:on 3:on 4:off 5:on 6:off
tcsd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
wpa_supplicant 0:off 1:off 2:off 3:off 4:off 5:off 6:off
xfs 0:off 1:off 2:off 3:off 4:off 5:off 6:off
yum-updatesd 0:off 1:off 2:off 3:off 4:off 5:off 6:off
To modify the settings of a service, use;
chkconfig [--level
