Cron job question

[Rick Hoekman]

Hello Matthew,

Thank you for taking the time explaining it to me!

Rick

Friday, August 22, 2003, 7:41:59 PM, you wrote:

MS> On Fri, Aug 22, 2003 at 07:18:16PM +0200, Rick Hoekman wrote:
>> I am getting this message every 5 minutes. Can somebody explain to me
>> why root apparently is not found here?
>> 
>> 
>> X-Original-To: root at somedomain.nl
>> Delivered-To: root at hoekmansysteembeheer.nl
>> From: root at somedomain.nl (Cron Daemon)
>> To: root at hoekmansysteembeheer.nl
>> Subject: Cron <root at somedomain> root /usr/libexec/atrun
>> X-Cron-Env: <SHELL=/bin/sh>
>> X-Cron-Env: <PATH=/etc:/bin:/sbin:/usr/bin:/usr/sbin>
>> X-Cron-Env: <HOME=/root>
>> X-Cron-Env: <LOGNAME=root>
>> X-Cron-Env: <USER=root> Date: Fri, 22 Aug
>> 2003 19:05:00 +0200 (CEST) root: not found
>> 

MS> You've made the classic mistake of confusing the system crontab
MS> (/etc/crontab) and the user specific crontabs that live in
MS> /var/cron/tabs.  These are quite different files.

MS> The system crontab /etc/crontab is not user specific: thus it has an
MS> extra column defining which user ID the command should be run as.  In
MS> general you shouldn't need to touch this file at all -- it's where
MS> standard stuff like the 'at' queue, newsyslog and the
MS> daily/weekly/monthly periodic functions are run from.  If you must
MS> alter this file, just edit it directly: cron(8) will pick up the
MS> changes in a minute or so.  In particular you do not need to use
MS> crontab(1) to manage this file.

MS> The per-user crontabs are what you would expect if you're familiar
MS> with the SysV or Linux style cron(8) daemon.  Each user has their own
MS> crontab file, which is managed using the crontab(1) command.  In
MS> general it's a good policy to use the per-user crontab stuff to add
MS> any new cron jobs for any user (including root) and leave the system
MS> /etc/crontab in it's default state.

MS> The error you're seeing suggests to me that what you've done is run
MS> crontab(1) on /etc/crontab, and the extra column containing the userid
MS> is being interpreted as a command that cron should run.  However,
MS> there is no command 'root', hence the error message.  To fix, make
MS> sute that /etc/crontab contains the default contents by copying over
MS> /usr/src/etc/crontab or running mergemaster(1).  Backup and delete the
MS> root crontab you've generated:

MS>     # crontab -l -u root > /tmp/root.crontab
MS>     # crontab -r -u root

MS> Now, if root.crontab contains substantively the same as /etc/crontab,
MS> you're done.  Otherwise, if you need to add some extra root cron jobs,
MS> edit /tmp/root.crontab to strip out the default stuff, leaving only
MS> you extra jobs.  Don't put a username in column 6 of the file: rather
MS> that should be the last column and contain the command to run, as per
MS> crontab(5).  Once edited to your liking load the new crontab file into
MS> the system:

MS>     # vi /tmp/root.crontab
MS>     # crontab -u root /tmp/root.crontab

MS>         Cheers,

MS>         Matthew