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Operating Systems Linux cron configuration
# 1  
Old 01-16-2011
cron configuration

I am programming a Western Digital ShareSpace network disk system.
I installed a cron from ipkg. (explained here: ShareSpace - Hacking WD MyBook World Ed)

Cron runs:
/etc $ ps -fe | grep cron
 6082 root        616 S < /opt/sbin/cron
18635 root        504 R < grep cron

I have programmed a crontab with a logfile.
The cron does not read my crontab file since the log file does not show a trace of cron.

Is there a way to know which crontab file uses cron? (Where does cron points to?)



Last edited by Scott; 01-17-2011 at 01:51 PM.. Reason: Code tags
# 2  
Old 01-16-2011
First off, your user needs to be in the cron group. Add them to the group like this:
usermod -a -G cron username

You must logout and log back into username for the new group to take effect.

Next let's prove that cron is operating properly. Run crontab -e to enter an interactive editor for your cron table.
* * * * * touch /home/username/filename

If cron is working, cron will create the file /home/username/filename and update its timestamp every minute.

See man 5 crontab for further details on how cron entries should be formatted.

If this works, but your logfile thing doesn't, please provide further details on what you're actually doing, i.e. your crontab entries and script files, otherwise we're just guessing.
# 3  
Old 01-17-2011
Thanks, I will try and let you know

---------- Post updated 17-01-11 at 08:59 AM ---------- Previous update was 16-01-11 at 09:42 PM ----------

Well it does not work.

The system is a Western Digital ShareSpace network disk with a Linux OS on it. I have already done that work on another WD MyBook disk and I had no problem.

First usermod is not found, I could have install it with ipkg but it is not available.
Then as I work as 'root' I would suspect root is in the cron group.
The cron process is /opt/sbin/cron.
With 'strings' command I find that the crontab is /opt/etc/crontab
The crontab reads:
# ---------- ---------- Default is Empty ---------- ---------- #
* * * * * touch /home/filename
1,5,10,15,20,25,30,35,40,45,50,55 * * * *  root /opt/scripts/rsync_backup

filename is not created by cron
I could run the touch command by hand and it worked of course.

Thanks for your help, I know the system is not standard....

Last edited by Scott; 01-17-2011 at 01:52 PM.. Reason: Code tags
# 4  
Old 01-17-2011
If you change crontab without notifying cron it will not pick up any changes. you could try SIGHUP or yust restart the cron process.
# 5  
Old 01-17-2011
The prefered -- at least by this sysadmin Smilie -- method for updating a table is to use the crontab command. Not only does it handle allthe pesky notification tasks, it does validate the syntax of the entries.
# 6  
Old 01-17-2011
Even rebooting the system did not do it.
Is there a log that I can install to see what cron does every minutes.

---------- Post updated at 01:16 PM ---------- Previous update was at 01:15 PM ----------

By the way I have an ssh issue is this the right thread for that?
# 7  
Old 01-17-2011
With regards to your cron problem - is crond running? The logfile is /var/log/cron, as mentioned in crond. There are also other configuration files mentioned in crontab.

Please start a new thread for your ssh issue.

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