Subject: Re: /var/cron -> /etc/cron
To: None <firstname.lastname@example.org>
From: Greg A. Woods <email@example.com>
Date: 04/11/1999 20:40:51
[ On Saturday, April 10, 1999 at 16:04:08 (-0400), Curt Sampson wrote: ]
> Subject: Re: /var/cron -> /etc/cron
> It seems to me that you have that anyway; you have either a config
> file in /etc stating where cron stuff lives, or a symlink in /etc
> stating where cron stuff lives.
I think config files are better -- they're far easier to manage with a
wider variety of configuration and change management tools.
While symlinks can indeed be considered to be configuration information,
and while it is possible to have some degree of control over them while
at the same time using simple text files for configuration management
(i.e. mtree can create them), I think they're generally less desirable.
We could do without mailwrapper and probably many other things if we
were to use symlinks exclusively for configuring various subsystems.
(BTW, although /etc/localtime is often a symlink, it can just as easily
be a copy of the target file too.)
> (As an alternative, I suppose you could specify the location with
> an option to cron at boot time, but then crontab has to communicate
> with cron to find out where all this is, and it won't work if cron's
> not running.)
Although I think there are several good ways to handle the issue of
having cron communicate it's boot-time settings to crontab, even if it's
not actually running at the time crontab is invoked (eg. write a
/var/run/cron.rc file at boot); I also think it's a damn good idea to
let the user know that cron's not running when they try to do anything
with their crontab file.
> Personally, I think that this stuff about config files is all
> getting quite complex, and I don't see that it's worth the kind of
> effort that would have to put in to implement it and implementing
> an upgrade system for the install for it. (With my original proposal,
> the upgrade is as simple as `ln -s ../var/cron /etc/cron'. If it
> fails, you're already on a new-type system, if not, you're upgraded.)
Yes, even without a config file to specify the location it's relatively
easy for anyone who really wants to relocate user crontabs to use a
symlink to do it, regardless of where cron actually looks for them.
> And still nobody on the `don't move it' side has put forth a more
> general study of where things should go in the filesystem, as those
> on the `please move it' side have.
I definitely want to move the user crontabs out of /var (though not
quite as much as I wanted to move the cron log! ;-).
Greg A. Woods
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