version 1.1, 2001/02/07 13:10:16
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version 1.2, 2001/09/07 14:54:47
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Line 24 the time of the server be kept accuratel
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Line 24 the time of the server be kept accuratel
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Accuracy involves |
Accuracy involves |
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I will explain the components of ntp and how they |
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interrelate on a LON-CAPA system |
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There are three relevant components here: |
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1. a correct /etc/ntp/step-tickers, |
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2. a correct /etc/ntp.conf |
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3. enabling xntpd for boot up |
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Without /etc/ntp.conf, /etc/rc.d/init.d/xntpd won't do anything. |
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With /etc/ntp.conf but without /etc/ntp/step-tickers, Gerd is correct |
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when he says: |
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> What I do know is that if the clock in the CMOS is off by too much,the normal |
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> ntp will not work. Instead, the clock has to be forced to synch initially,and |
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> from then on can be automatically adjusted. |
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The unix commands for Gerd's manual approach are: |
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/etc/rc.d/init.d/xntpd stop |
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/usr/sbin/ntpdate ntp.msu.edu (or whatever your ntp server is) |
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/etc/rc.d/init.d/xntpd start |
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To force xntpd to avoid the offset problem, defining |
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/etc/ntp/step-tickers does the trick. |
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With /etc/ntp.conf and /etc/ntp/step-tickers, xntp still may not |
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work (depending on whether the last instruction was followed |
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for the LON-CAPA installation, see |
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http://install.lon-capa.org/docs/3.1/instructions_with_cd.html) |
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Making sure xntp starts up upon boot time should simply |
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be a matter of: |
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/sbin/chkconfig xntpd on |
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Finally, the correct settings for /etc/ntp.conf |
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and /etc/ntp/step-tickers are: |
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1 line with the ip address of your ntp server |
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For instance: |
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echo "whistler.sfu.ca" > /etc/ntp/step-tickers |
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echo "whistler.sfu.ca" > /etc/ntp.conf |
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Everyone is currently setting these and other LON-CAPA conf |
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files manually after cvs upgrades, because |
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there were several parties who were |
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* doing different things |
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* in different ways |
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* for different reasons |
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* for different institutions |
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* for their machine-specific configurations |
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I was not able to make everyone happy with |
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"make configinstall". For the future, we (Guy and I) do think |
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we've come up with a new way to do everything |
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for everyone for updating configuration files |
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as the CVS source repository changes. |
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-Scott |
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</pre> |
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</body> |
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</html> |