Crontab is not working

Ejdaha · 11-28-2009, 09:57 AM

Dear all

Here is the steps I've done. Please correct me if I made anything wrong. My cron job is not working

Code:

user@localhost:~> ls -lh test.dat
/bin/ls: test.dat: No such file or directory
user@localhost:~> date
Sat Nov 28 19:18:33 GMT+4 2009
user@localhost:~> crontab -e
crontab: no changes made to crontab
user@localhost:~> crontab -e
crontab: installing new crontab
user@localhost:~> crontab -l

# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.XXXXkkSAid installed on Sat Nov 28 19:18:52 2009)
# (Cron version V5.0 -- $Id: crontab.c,v 1.12 2004/01/23 18:56:42 vixie Exp $)
19 19 * * * /bin/echo "test" >> /opt/user/test.dat

user@localhost:~> date
Sat Nov 28 19:18:56 GMT+4 2009
user@localhost:~> date
Sat Nov 28 19:19:02 GMT+4 2009
user@localhost:~> ls -lh test.dat
/bin/ls: test.dat: No such file or directory
user@localhost:~>

repo · 11-28-2009, 10:01 AM

Quote:

user@localhost:~> ls -lh test.dat
/bin/ls: test.dat: No such file or directory
user@localhost:~>

are you in /opt/user/ ?

try

Code:

ls -lh /opt/user/test.dat

Ejdaha · 11-28-2009, 10:03 AM

Sure I'm there

Quote:

/bin/ls: /opt/user/test.dat: No such file or directory
user@localhost:~>

repo · 11-28-2009, 10:07 AM

Do you have permission to write to /opt/user?
Take a look in the lofgfiles for errrors from cron.

Ejdaha · 11-28-2009, 10:12 AM

Yes, I 've permission on that folder as I can create a file there

Quote:

user@localhost:~> touch tet
user@localhost:~> ls tet
tet
user@localhost:~>

I opened /var/log/messages file and see the following lines:

Nov 28 19:18:52 localhost crontab[4279]: (user) END EDIT (user)
Nov 28 19:18:54 localhost crontab[4283]: (user) LIST (user)
Nov 28 19:19:01 localhost /usr/sbin/cron[4405]: (user) RELOAD (tabs/user)

What does it mean? There's no error

repo · 11-28-2009, 10:16 AM

Could you post the output from

Code:

pwd

Ejdaha · 11-28-2009, 10:20 AM

Please see the output

Quote:

user@localhost:~> pwd
/opt/user

repo · 11-28-2009, 10:34 AM

try

Code:

* * * * * /bin/echo "test" >> /opt/user/test.dat

It will run every minute

Ejdaha · 11-30-2009, 02:43 AM

Thanks repo for your help. It's working for every minute, but not working for specific date and time. What's the reason?

repo · 11-30-2009, 03:38 AM

Quote:

19 19 * * * /bin/echo "test" >> /opt/user/test.dat

should launch the crontab at 7h19 pm

Ejdaha · 11-30-2009, 03:51 AM

Could you explain why the following cron is not working?

Quote:

user@localhost:~> date
Mon Nov 30 13:17:43 GMT+4 2009
user@localhost:~> crontab -l
# DO NOT EDIT THIS FILE - edit the master and reinstall.
# (/tmp/crontab.XXXXvnPD7i installed on Mon Nov 30 13:17:37 2009)
# (Cron version V5.0 -- $Id: crontab.c,v 1.12 2004/01/23 18:56:42 vixie Exp $)
18 13 * * * /bin/echo "test" >> /opt/user/test.dat
user@localhost:~> date
Mon Nov 30 13:18:02 GMT+4 2009
user@localhost:~> ls -lh test.dat
/bin/ls: test.dat: No such file or directory
user@localhost:~> ls -lh /opt/user/test.dat
/bin/ls: /opt/user/test.dat: No such file or directory
user@localhost:~>

Ejdaha · 11-30-2009, 03:56 AM

Interesting issue, when I change the cron to run on every minute, it works... Where is the problem??

timmeke · 11-30-2009, 06:27 AM

crontab -e edits a file in cron's spool folder, where all users' cron jobs are stored.
Each minute, cron will check the spool folder for updates and ingest them if found.
So, if you schedule a job to run on minute 18, while you are on minute 17, it is possible that
cron will miss your update.

Try leaving 2-3 minutes between the time when you change the crontab and the job execution time,
allowing cron to detect and incorporate the update.

Note: this is also why you can't schedule cron jobs to the second (or millisecond) levels: cron only
checks for updates once per minute. Have a look at the cron jobs scheduled in /etc/cron*, like /etc/crontab.

chrism01 · 11-30-2009, 07:30 PM

Good advice. Also, if cron has an issue, it'll usually email the cron job owner or root with a summary.
Try mail or mailx at the cli as you and root to see if it said anything.

Ejdaha · 12-01-2009, 07:09 AM

Thank you guys. I've solved it using and investigating the cron log. There I saw that it doesn't run for the first time, it just RELOAD, but runs for the next time

I have another question, how can I get the current date and time when my cron will run? I configured it, and now want to know the current dates when it will run "without running it"

Thanks in advance