timekeeping on jail servers

[John Webster]

--On Friday, December 21, 2007 13:51:29 -0500 Bill Moran <wmoran at potentialtech.com> wrote:

> In response to John Webster <jwebster at es.net>:

>> > 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.
> 
> Umm ....
> 
> At that point, why not just run ntpd?  You've basically replaced it
> with a script anyway.
> 

My suggestions are based on the OP about ntpd binding to everything.


> Besides, it's not that easy.  As Chuck pointed out, ntpdate calls
> adjtime() and exits, which means an adjustment might already be in
> progress when you you call it again.  I don't know if ntpdate checks
> the return pointer from adjtime() to avoid multiple adjustment
> requests.

Just out of curiosity, why run it more that once a day? Or for
that matter every couple of days?