Many Linux distributions run daemons most of us will never use.
Most of these daemons are loaded by scripts. Where these scripts are and what
they are called depends on your Linux distribution. Slackware set-up scripts
are buried in /etc/rc.d/rc.*.
Before you proceed, a knowledge of Unix shell script programming
would be a definite asset. However, if you have no experience writing Unix
shell scripts, what follows is probably the quickest introduction to shell
script programming ever written.
Take the following shell script:
#!/bin/sh echo "hello world"
#echo "good bye cruel world" |
The previous code will echo the string "hello world". Shell scripts
must contain the the line
at the very top line.
After that every line is executed as if you had typed it at the keyboard (think
of shell scripts as nothing more then glorified keyboard macros).
Lines which begin with a '#' are said to be commented out because
they do not get executed by the shell. Most start-up scripts when they load
daemons look like:
if somecondition
do something
fi |
What you want to do is comment out every line starting with the
statement and ending with the
statement.
If you want to find where a daemon is loaded,
search the start-up scripts for the name of the daemon. If I wanted to find
where inetd is loaded in Slackware I would do the following:
$ cd /edt/rc/d $grep -n inetd rd.* |
inetd allows people to do things like telnet, ftp, and send talk
requests to your machine. If you never use your system as a server or need to
access any of its services remotely you can remove inetd.
lpd is used to print files on your printer using the
lpr command. If you never print on your Linux
box you can remove lpd. If, however, you own a HP Deskjet ™ printer and
would like to print, I highly recommend the package I put together called
dj-printcap which is available at:
ftp://sunsite.unc.edu/pub/Linux/system/Printing/dj-printcap.tar.gz
These two daemons are used to run an NFS server. If you never use
your Linux system as an NFS server you can safely remove these two daemons.
The portmap daemon is used to handle RPC services. If you do not
run an NFS server or any other RPC programs you can remove portmap.
sendmail is another daemon which requires a fair bit of memory.
If you never use your Linux box as a relay for sending e-mail or you never
receive mail on your Linux box, you can probably remove sendmail. If you do send
e-mail from your Linux box most e-mail clients can be set-up to send e-mail
from another mail server.
There may be other daemons your system starts up which you do
not need. Remove what you feel you have to. Two daemons which you must run are
syslogd and klogd.