Comments on: Make Sure Your Machine Is On The Correct Time With ntpdate http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/ Enhancing your Ubuntu experience! Thu, 02 Feb 2012 10:29:43 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Death Insurance WebLog » Blog Archive » The Answer Guy 38: How 'ntpdate' finds IP addresses? http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-976 Death Insurance WebLog » Blog Archive » The Answer Guy 38: How 'ntpdate' finds IP addresses? Wed, 18 Jul 2007 12:34:23 +0000 http://ubuntu-tutorials.com/?p=276#comment-976 [...] Make Sure Your Machine Is On The Correct Time With ntpdate : Ubuntu … Note that the accuracy and reliability of ntpdate depends on the number of servers, the number of polls each time it is run and the interval between runs. http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/ [...] [...] Make Sure Your Machine Is On The Correct Time With ntpdate : Ubuntu … Note that the accuracy and reliability of ntpdate depends on the number of servers, the number of polls each time it is run and the interval between runs. http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/ [...]

]]> By: James Tait http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-975 James Tait Thu, 22 Feb 2007 17:23:03 +0000 http://ubuntu-tutorials.com/?p=276#comment-975 Using ntpdate in this way is a very bad idea. ntpdate should be run at boot time and only very rarely thereafter -- ntpd will keep your clock in sync, take account of 'drift' to make sure your clock stays reasonably accurate even without a network connection, and won't end up with all the world's Ubuntu boxes hitting the NTP server at the same time. This is actually what the "Keep clock synchronized with Internet servers" checkbox in the "Adjust Date and Time" dialogue box does -- it starts and stops ntpd. I'd correct this tutorial if I were you. Using ntpdate in this way is a very bad idea. ntpdate should be run at boot time and only very rarely thereafter — ntpd will keep your clock in sync, take account of ‘drift’ to make sure your clock stays reasonably accurate even without a network connection, and won’t end up with all the world’s Ubuntu boxes hitting the NTP server at the same time. This is actually what the “Keep clock synchronized with Internet servers” checkbox in the “Adjust Date and Time” dialogue box does — it starts and stops ntpd. I’d correct this tutorial if I were you.

]]> By: saharvetes http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-974 saharvetes Tue, 20 Feb 2007 05:14:08 +0000 http://ubuntu-tutorials.com/?p=276#comment-974 No, please don't use ntpdate! See <a href="http://lists.debian.org/debian-user/2002/12/msg04091.html" rel="nofollow">this</a>. You ought to update your post, IMHO. No, please don’t use ntpdate! See this. You ought to update your post, IMHO.

]]> By: Lamont Peterson http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-968 Lamont Peterson Tue, 20 Feb 2007 04:58:39 +0000 http://ubuntu-tutorials.com/?p=276#comment-968 <code>ntpdate</code> should never be run from cron. It is well known to cause problems, like the clock ending up farther off than it would have been otherwise due to repeated use of <code>ntpdate</code>. Running <code>ntpdate</code> from cron is such a bad idea, that ntp's authors decided to remove the <code>ntpdate</code> command entirely a couple of years ago. It appeaars that they changed their minds. <code>ntpd</code> is a very tiny daemon and the basic setup needed for desktop use is extremely simple. Not running "one more daemon", though an understandable reason on it's own, doesn't make sense with <code>ntpd</code>. On my notebooks, I just run <code>ntpdate</code> about once a month and let the system clock keep things close from there. The nature of the way notebooks are used and the varying powersources supplying the hardware clock at different times, means that their hardware clocks will drift more than the typical desktop machine's. Even running <code>ntpd</code> on a notebook that doesn't always have a network connection produces better results. ntpdate should never be run from cron. It is well known to cause problems, like the clock ending up farther off than it would have been otherwise due to repeated use of ntpdate.

Running ntpdate from cron is such a bad idea, that ntp’s authors decided to remove the ntpdate command entirely a couple of years ago. It appeaars that they changed their minds.

ntpd is a very tiny daemon and the basic setup needed for desktop use is extremely simple. Not running “one more daemon”, though an understandable reason on it’s own, doesn’t make sense with ntpd.

On my notebooks, I just run ntpdate about once a month and let the system clock keep things close from there. The nature of the way notebooks are used and the varying powersources supplying the hardware clock at different times, means that their hardware clocks will drift more than the typical desktop machine’s. Even running ntpd on a notebook that doesn’t always have a network connection produces better results.

]]> By: dontturnaway http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-973 dontturnaway Mon, 19 Feb 2007 23:32:55 +0000 http://ubuntu-tutorials.com/?p=276#comment-973 sudo vim /etc/cron.hourly/setclock.cron ---------------------------- #and within it: #!/bin/bash clock=timeserverofyourchoicehere /usr/sbin/ntpdate -s -u $clock >& /dev/null /sbin/hwclock --adjust /sbin/hwclock --systohc ------------------------------ Replace timeserverofyourchoicehere above with the time server of your choice, maybe something close to you in pool.ntp.org. then: sudo chmod +x /etc/cron.hourly/setclock.cron It just works! As another poster said, you can use ntpd instead, but ntpdate is very simple for most and people have had problems (just see UbuntuForums for many examples) with ntpd in Ubuntu and getting it working right. Plus, if I'm running a desktop system I like ntpdate via cronjob rather than ntpd because I don't have extra computers to update and I don't want an extra daemon running all the time just for keeping the time on one system updated. sudo vim /etc/cron.hourly/setclock.cron

—————————-
#and within it:

#!/bin/bash

clock=timeserverofyourchoicehere

/usr/sbin/ntpdate -s -u $clock >& /dev/null

/sbin/hwclock –adjust

/sbin/hwclock –systohc
——————————

Replace timeserverofyourchoicehere above with the time server of your choice, maybe something close to you in pool.ntp.org.

then:

sudo chmod +x /etc/cron.hourly/setclock.cron

It just works!

As another poster said, you can use ntpd instead, but ntpdate is very simple for most and people have had problems (just see UbuntuForums for many examples) with ntpd in Ubuntu and getting it working right. Plus, if I’m running a desktop system I like ntpdate via cronjob rather than ntpd because I don’t have extra computers to update and I don’t want an extra daemon running all the time just for keeping the time on one system updated.

]]> By: jorge http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-972 jorge Mon, 19 Feb 2007 21:47:52 +0000 http://ubuntu-tutorials.com/?p=276#comment-972 Don't set your clock via cron and ntpdate, use ntpd instead: http://episteme.arstechnica.com/eve/forums/a/tpc/f/96509133/m/982008055631/r/982008055631#982008055631 This works in Ubuntu as well as Debian. Don’t set your clock via cron and ntpdate, use ntpd instead:

http://episteme.arstechnica.com/eve/forums/a/tpc/f/96509133/m/982008055631/r/982008055631#982008055631

This works in Ubuntu as well as Debian.

]]> By: Ubuntu Tutorials http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-971 Ubuntu Tutorials Mon, 19 Feb 2007 19:31:39 +0000 http://ubuntu-tutorials.com/?p=276#comment-971 Menachem - if you don't have a connection it will not work, sorry. Menachem – if you don’t have a connection it will not work, sorry.

]]> By: Simon http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-970 Simon Mon, 19 Feb 2007 19:24:03 +0000 http://ubuntu-tutorials.com/?p=276#comment-970 Strange thing, that on my Ubuntu install I have the problem that after 24 hours the clock is 5 minutes in the future. I use Archlinux on the same computer and there isn't this problem. I'm syncing Ubuntu's clock every hour to fix this problem but on my Archlinux I don't have to do this. Strange. Strange thing, that on my Ubuntu install I have the problem that after 24 hours the clock is 5 minutes in the future. I use Archlinux on the same computer and there isn’t this problem.
I’m syncing Ubuntu’s clock every hour to fix this problem but on my Archlinux I don’t have to do this. Strange.

]]> By: Menachem http://ubuntu-tutorials.com/2007/02/19/make-sure-your-machine-is-on-the-correct-time-with-ntpdate/#comment-969 Menachem Mon, 19 Feb 2007 18:27:34 +0000 http://ubuntu-tutorials.com/?p=276#comment-969 What happens if you are using the computer without an internet connection? Do errors get displayed, or is it silent? What happens if you are using the computer without an internet connection? Do errors get displayed, or is it silent?

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