timekeeping on jail servers
John Webster
jwebster at es.net
Fri Dec 21 10:44:45 PST 2007
--On Friday, December 21, 2007 13:24:40 -0500 Bill Moran <wmoran at potentialtech.com> wrote:
> In response to John Webster <jwebster at es.net>:
>>
>> --On December 21, 2007 11:23:03 AM -0500 Bill Moran <wmoran at potentialtech.com> wrote:
>>
>> > In response to shinny knight <sh1nny_kn1ght at yahoo.com>:
>> >
>> > The reason that is not recommended is that it results in sudden steps
>> > of the clock. Occasionally, these steps go backwards. Software that
>> > is very sensitive to time changes (make processes, database servers,
>> > anything doing calculations WRT time) can break, crash, or work
>> > inaccurately.
>>
>> ntpdate -B should slew the time slowly. (According to the manpage.)
>
> Not generally suitable for cron because it can take longer to slew
> than it does for the next cron execution to occur, which would then
> result in multiple ntpdate programs fighting each other (not sure
> what the effect of this would be).
>
If I were doing it I would write a script with locking in order
to ensure multiple jobs don't fight. Simple.
Happy Holidays!
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