Novice administrator cron problem

[Alexis Rosen]

In article <1991Mar6.215758.20177 at magnus.ircc.ohio-state.edu> talley at hpuxa.ircc.ohio-state.edu (James T. Talley) writes:
>I suspect that my question falls into the novice sys admin
>category, but I thought that I would try it out here before
>sending it to one of the heavy traffic unix newsgroups.
>
>The problem is simple -- every job I put into a crontab file
>seems to be run twice.  The cron log shows two separate entries
>for each job and frequently the second one will give error
>messages because the files it wants are busy.  This is on a Mac
>IIci with A/UX 2.0.  The cron jobs I've tried are for system
>accounting, UUCP (see example below), and simply testing the cron
>problem.

You may indeed be at fault but you have probably tripped over a bug in A/UX.
In two years I've seen this happen three times, so it's not exactly common.

What's happening is that you've got two copies of cron running. Look-
$ ps -ef |grep cron
    root   125     1  0  Mar  4  ?        0:07 /etc/cron
    root 21856     1  1 15:31:25 ?        0:00 /etc/cron
    root 21858 21850  4 15:31:29 a0       0:00 grep cron

It's possible to fire up a second cron by hand, and it's possible that you
did something like cron <mycrontab at some point, which would also cause this.
It's easy to forget to use "crontab" instead of "cron."

As for a bug report: I haven't got a clue as to how this happens spontaneously
so I have nothing useful to report. I wish it were otherwise.

---
Alexis Rosen
Owner/Sysadmin, PANIX Public Access Unix, NY
{cmcl2,apple}!panix!alexis