Unix Boot Sequence

UNIX for Advanced & Expert Users
1

Hello all Unix fans.

What files are involved in the Unix boot sequence,
i guess there is alot of them but some must be the main files?

For example the service SENDMAIL starts on our Unix machine
where should i edit so that it will not start at BOOT.
initd.conf? rc2.d?

I hope you understand my question and i know this is really basic but i hope you have time to help me out.

/Nick

2

To disable sendmail so that it does not start at bootup,

rename /etc/rc2.d/S88sendmail to

/etc/rc2.d/s88sendmail_disable

this will prevent sendmail from start at bootup

Note
/etc/rc2.d/s88sendmail_disable

s88sendmail_disable is all lower case, it most be
lower case to disable sendmail or any other daemon
in rc

3

you might want to take a look here: http://userpages.umbc.edu/~jack/ifsm498d/multi-user.html
best regards, eNTer

4

This also depends very much on which Unix variant you are using. On a Linux system, it also depends on your distribution! For example, HP-UX 9, HP-UX 10.20, Slackware Linux, Redhat Linux all have their own quirks... The two HP-UX variants do it differently (changed in version), and the Linux variants do it differently (one uses a more BSD rc and the other uses SYSV style...).

So... The whole point of this is to please post all you can about your system!

5

All scripts and links are executed from the /etc/rc[n].d/ directories. Many of these may be files located in these locations or links to files or scripts in /etc/init.d/. Usually you can stop and start any service (if the script allows) by issuing a request from the command line.

# /etc/rc2.d/S80sshd stop

... as an example, to stop the SSH daemon.

If the file begins with an 'S' then it is utilised when the system comes up, if it starts with a 'K' it stops processes when the system goes down.

We disable these scripts by renaming them with lowercase 's' and 'k' - this way they are never run whenthe machine comes up.

Hope this helps

6

On FreeBSD,

you can edit the /etc/rc.conf to stop sendmail, like so:

sendmail_enable="NONE"

As already said, it depends upon which version of Unix you are using :wink:

7

sajjan2,

Here's a decent overview of the startup sequence:

http://docs.rinet.ru:8080/UNIXs/ch16.htm

Biker
Systems/Network Administrator
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