timekeeping on jail servers

[John Webster]

--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!