Installation guide

S13portmap -> ../init.d/portmap
S15mdmonitor -> ../init.d/mdmonitor
S15zebra -> ../init.d/zebra
S16bgpd -> ../init.d/bgpd
S16ospf6d -> ../init.d/ospf6d
S16ospfd -> ../init.d/ospfd
S16ripd -> ../init.d/ripd
S16ripngd -> ../init.d/ripngd
S20random -> ../init.d/random
S24pcmcia -> ../init.d/pcmcia
S25netfs -> ../init.d/netfs
S26apmd -> ../init.d/apmd
S27ypbind -> ../init.d/ypbind
S28autofs -> ../init.d/autofs
S40smartd -> ../init.d/smartd
S44acpid -> ../init.d/acpid
S54hpoj -> ../init.d/hpoj
S55cups -> ../init.d/cups
S55sshd -> ../init.d/sshd
S56rawdevices -> ../init.d/rawdevices
S56xinetd -> ../init.d/xinetd
S58ntpd -> ../init.d/ntpd
S75postgresql -> ../init.d/postgresql
S80sendmail -> ../init.d/sendmail
S85gpm -> ../init.d/gpm
S87iiim -> ../init.d/iiim
S90canna -> ../init.d/canna
S90crond -> ../init.d/crond
S90xfs -> ../init.d/xfs
S95atd -> ../init.d/atd
S96readahead -> ../init.d/readahead
S97messagebus -> ../init.d/messagebus
S97rhnsd -> ../init.d/rhnsd
S99local -> ../rc.local
As illustrated in this listing, none of the scripts that actually start and stop the services are located in
the /etc/rc.d/rc5.d/ directory. Rather, all of the files in /etc/rc.d/rc5.d/ are symbolic links
pointing to scripts located in the /etc/rc.d/init.d/ directory. Symbolic links are used in each of
the rc directories so that the runlevels can be reconfigured by creating, modifying, and deleting the
symbolic links without affecting the actual scripts they reference.
The name of each symbolic link begins with either a K or an S. The K links are processes that are
killed on that runlevel, while those beginning with an S are started.
The init command first stops all of the K symbolic links in the directory by issuing the
/etc/rc.d/init.d/<command> stop command, where <command> is the process to be killed. It
then starts all of the S symbolic links by issuing /etc/rc.d/init.d/<command> start.
Note
After the system is finished booting, it is possible to log in as root and execute these same
scripts to start and stop services. For instance, the command /etc/rc.d/init.d/httpd
stop stops the Apache HTTP Server.
Each of the symbolic links are numbered to dictate start order. The order in which the services are
started or stopped can be altered by changing this number. The lower the number, the earlier it is
started. Symbolic links with the same number are started alphabetically.
⁠Chapt er 33. Boot Process, Init , and Shut down
34 3