NTP - how to slack it best?

Yalla-One · 09-17-2006, 12:36 PM

This got me motivated to update my own rc.ntp script - could someone please advise how to make a shell-script read the /etc/ntp.conf and grab the preferred server based on the "prefer" statement in the config file:

Code:

server 0.no.pool.ntp.org prefer
server 1.europe.pool.ntp.org
server 2.europe.pool.ntp.org

Ie. scan the prefer keyword on a line beginning with server and thus extract 0.no.pool.ntp.org from this line, and use that server for the initial ntpdate command in the beginning of the rc.ntp script ?

-Y1

Woodsman · 09-17-2006, 03:30 PM

I have posted my mini how-to about configuring the NTP software with Slackware:

Configuring the NTP Daemon

Scripts and config files are included.

All comments and corrections are appreciated.

ralvy · 10-08-2006, 08:41 AM

Quote:

Originally Posted by Woodsman

I have posted my mini how-to about configuring the NTP software with Slackware:

Configuring the NTP Daemon

Scripts and config files are included.

All comments and corrections are appreciated.

Thanks for your thorough article on Slackware and ntp. Concerning this part of the article

Quote:

Some caveats. The Slackware /etc/rc.d/rc.inet1 initializes the dhcpc daemon such that dhcpcd will overwrite /etc/ntp.conf. Avoid that problem by adding an -N switch to all of the /etc/rc.d/rc.inet1 lines starting the dhcpc daemon. Or, rather then modify the rc.d scripts, edit etc/rc.d/rc.inet1.conf for the affected network card by adding DHCP_KEEPNTP[x]="yes". People using static IP addresses need not worry about this caveat.

I have opted instead to not touch rc.d scripts to handle this, other than rc.local. That way, if any of the other rc scripts change, I don't need to worry about editing them again. First, I save a copy of my edited /etc/ntp.conf file to /etc/ntp.conf.good. Then I put this in /etc/rc.d/rc.local:

Code:

ntpdate 0.us.pool.ntp.org 1.us.pool.ntp.org
ntpd -c /etc/ntp.conf.good

That way, if another rc.d script stomps on /etc/ntp.conf, I don't have to worry about it.

Woodsman · 10-08-2006, 04:32 PM

Quote:

I have opted instead to not touch rc.d scripts to handle this, other than rc.local . . .

Good point and thank you for the feedback. One does not need to directly modify the rc.inet1 script at all. I therefore revised that paragraph. Instead simply edit the rc.inet1.conf file, which basically is a container of variables for the rc.inet1 script.

ralvy · 10-08-2006, 06:00 PM

Quote:

Originally Posted by Woodsman

Good point and thank you for the feedback. One does not need to directly modify the rc.inet1 script at all. I therefore revised that paragraph. Instead simply edit the rc.inet1.conf file, which basically is a container of variables for the rc.inet1 script.

I see. I remember thinking about that a while ago and decided I didn't want to have to remember if that particular .conf file was something I would have to examine after an upgradepkg or not. Using rc.local for this just removed one more .conf file I had to deal with. Probably not really the Slack way of doing things, though.

allend · 10-09-2006, 08:43 AM

I also start NTP using a script called from rc.local. My script actually copies a known good version of my configuration file with my localised settings to the active configuration file before launching ntpd. I do this as once NTP is up and running, you can easily forget all about about it, until you lose your configuration with a package update or reinstall.

I do remember to check things occasionally with 'ntpd -p' though!

ralvy · 10-09-2006, 08:52 AM

Quote:

Originally Posted by allend

I also start NTP using a script called from rc.local. My script actually copies a known good version of my configuration file with my localised settings to the active configuration file before launching ntpd. I do this as once NTP is up and running, you can easily forget all about about it, until you lose your configuration with a package update or reinstall.

I do remember to check things occasionally with 'ntpd -p' though!

You can just use ntpd -c and not have to copy over anything at all.

allend · 10-09-2006, 10:11 PM

ralvy
Thanks for the tip. Onbviously were both trying to access the forum at about the same time, otherwise I would not have gotten involved.

Michielvw · 10-10-2006, 01:32 PM

pretty good mini-howto

would it be perhaps a nice idea to include a logrotate script for ntp as well? not sure how big the ntp.log will become?

secondly, if I want to have other pc's in my lan use my main server for their ntp pooling .. how would I go about that??

Woodsman · 10-10-2006, 02:27 PM

Quote:

pretty good mini-howto

Thank you.

Quote:

would it be perhaps a nice idea to include a logrotate script for ntp as well? not sure how big the ntp.log will become?
secondly, if I want to have other pc's in my lan use my main server for their ntp pooling .. how would I go about that?

I started to write a response for this thread, but by the time I finished I realized I had created sufficient text to revise the how-to. So please revisit Installing NTP for additional instructions. And thanks for the feedback!

PDock · 10-11-2006, 05:58 AM

Woodsman thanks for your NTP Howto. Hopefully most poeple using dialup via ppp know the script /etc/ppp/ip-up is a good place to call your rc.ntp.

ppd

Woodsman · 10-11-2006, 05:38 PM

Quote:

Hopefully most poeple using dialup via ppp know the script /etc/ppp/ip-up is a good place to call your rc.ntp.

Noted. Revised. Updated. Thank you!

checklist · 10-13-2006, 11:33 AM

When trouble shooting scripts, kernel, etc. I turn off NTP at boot time. ie " Slackware nohotplug nontp "

if grep -wq nontp /proc/cmdline ; then
echo "Not loading NTP damon by request."
else

# startup script here #

fi

Charlie