Re: how to use "ntpd" to emulate "ntpdate"?

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At 20:37 1/30/2004, you wrote:
I missed the start of this thread, but does "ntpdate <server>" not do what
you want? I run it here from a cron job every 2 hours, seems to work
fine.

Here's the link someone posted explaining why ntpdate is being deprecated and why it's so inferior:


http://www.ntp.org/ntpfaq/NTP-s-config.htm

Of course, "inferior" means that your time may be off by as much as a second or so, which is fine for most of us but unthinkably awful for ntpd which usually keeps my server in sync by less than a millisecond. That difference in perception is why most of us see ntpdate as a useful thing but why the maintainers are going to kill it off.

Lest others read Michael's post as suggesting that an ntpdate run every two hours is a good thing for a /server/, I thought I should add some comments. Most servers should run ntpd in order to keep time synchronized as closely as possible, and most organizations should run at least one ntpd server to which their computers can synchronize. Please note that, in Michael's example, he is synchronizing to an /internal/ server so hitting it every two hours is just fine.

ntpdate every hour or two is great for clients connecting to an internal server, but it would not be a good solution for a server. This is partly due to accuracy issues, and partly since it generates fairly large traffic spikes for the public servers and causes an unnecessarily high amount of traffic and load for them. So be a good netizen, run one or two ntpd boxes on your network somewhere, and sync all other boxes to those.

And, if you /insist/ on using ntpdate regularly against public servers, PLEASE:

        1. Do not run as frequently. Update only once or twice a day at most.

2. Set non-standard times. If a million computers all hit ntpdate at midnight, or every hour on the dot (1:00, 2:00...) the public servers are going to have huge problems. Set yours up to update at 3:37am and 3:37pm or odd times like that.

3. Rethink your strategy and try to stop doing regular ntpdate updates.


-- Rodolfo J. Paiz rpaiz@xxxxxxxxxxxxxx http://www.simpaticus.com




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