增加服務
語法：
# rc-update add scriptname runlevels
範例：
# rc-update add vixie-cron default
* service vixie-cron added to runlevel default
刪除服務
語法：
# rc-update del scriptname runlevels
# rc-update del scriptname
範例：
# rc-update del dhcpd default
* service dhcpd removed from runlevel default
runlevels 可以是 boot / default ….
[@more@]
列出可用的 Script 和運行層級
# rc-update show
bootmisc | boot
devfs | sysinit
dmesg | sysinit
fsck | boot
hostname | boot
keymaps | boot
killprocs | shutdown
kmod-static-nodes | sysinit
local | default
localmount | boot
loopback | boot
modules | boot
mount-ro | shutdown
mtab | boot
net.eth0 | default
netmount | default
ntp-client | default
procfs | boot
root | boot
savecache | shutdown
sshd | default
swap | boot
swapfiles | boot
swclock | boot
sysctl | boot
sysfs | sysinit
termencoding | boot
tmpfiles.dev | sysinit
tmpfiles.setup | boot
udev | sysinit
udev-mount | sysinit
urandom | boot
# rc-status
Runlevel: default
net.eth0 [ started ]
ntp-client [ started ]
sshd [ started ]
netmount [ started ]
local [ started ]
Dynamic Runlevel: hotplugged
Dynamic Runlevel: needed
Dynamic Runlevel: manual