cron/anacron

[Alan McKinnon]

On Thursday 11 May 2006 16:45, Toby Kelsey wrote:
> > cron was designed to run on machines that are up all the time. No
> > sane developer is going to try and extend it - it works, it works
> > well and it ain't broke.
>
> Actually most versions of cron have always failed to cope with
> changes to the clock even with an always-on machine, and all
> machines have down-time which cron ought to be able to handle but
> doesn't.  The manual administrative interventions this then
> requires is something I thought Ubuntu wanted to avoid.

Frankly, I don't think cron should concern itself with faulty time 
issues. That's a problem that occurs elsewhere, and should be fixed 
elsewhere. I think cron should stick to "if the small hand is on X 
and the big hand is on Y, then do Z".

My Dapper is using Vixie cron 3. I see that Paul amended this 
behaviour for 4.1 to account for small changes less than three hours 
- apparently because of daylight savings issues. I can live with 
that.

> > The /etc/cron.*ly files have nothing whatsoever to do with cron
> > or anacron.
>
> I suppose in some bizarro world /etc/cron.monthly could have
> nothing to do with cron or anacron in the same way that
> /etc/login.defs could have nothing to do with login. But names have
> meanings, and we are in real world:
>
> $ dpkg -S /etc/cron.monthly
> scrollkeeper, anacron, cron: /etc/cron.monthly
>
> Note also that run-parts (debianutils) is not mentioned.

<sigh> you know what I mean. The OP was trying to grasp how all the 
related bits as implemented on his machine fit together. With that in 
mind, I was highlighting that cron is natively unaware 
of /etc/cron.*ly, those dirs are used by run-parts. The packager has 
set up the cron *package* to create those dirs knowing full well that 
he will add three calls to run-parts in /etc/crontab

-- 
If only me, you and dead people understand hex, 
how many people understand hex?

Alan McKinnon
alan at linuxholdings dot co dot za
+27 82, double three seven, one nine three five