Обсуждение: Crontab problem with backup

I was trying to backup a database called "old_db".The following lines
inserted into either root crontab file or postgres crontab file failed
either to produce any output or created an empty file caled
"old_db_hr9.tgz" in the /backups/hour/ directory..

0 9 * * 1-5 postgres pg_dump --format=t old_db >
/backups/hour/old_db_hr9.tgz

0 18 * * 5 postgres pg_dump --format=t old_db >
/backups/week/old_db_friday.tgz


What logs do I need to check to find the problem? What might be a way to
test the script?

On April 14, 2006 06:58 pm, Kirti <kirti@unswalumni.com> wrote:

> What logs do I need to check to find the problem?

Wherever your system logs the output from cron.  RedHat Linux and
derivatives will have a /var/log/cron or something similar (if you happen
to be running Linux).  The postgres user probably got email about it, too.

> What might be a way to
> test the script?

su - postgres
run the command

This will uncover most problems, outside of obscure path differences between
a normal login session and what cron provides.   Also make sure the user is
allowed to execute cron jobs.

Your cron log most likely will tell you what went wrong, though.

--
Alan

Kirti <kirti@UNSWalumni.com> writes:
> I was trying to backup a database called "old_db".The following lines
> inserted into either root crontab file or postgres crontab file failed
> either to produce any output or created an empty file caled
> "old_db_hr9.tgz" in the /backups/hour/ directory..

> 0 9 * * 1-5 postgres pg_dump --format=t old_db >
> /backups/hour/old_db_hr9.tgz

> 0 18 * * 5 postgres pg_dump --format=t old_db >
> /backups/week/old_db_friday.tgz

Are you sure you've got the crontab file format correct?  On my machine,
at least, there's no userid column.

            regards, tom lane

Tom Lane wrote:
> Kirti <kirti@UNSWalumni.com> writes:
> > I was trying to backup a database called "old_db".The following lines
> > inserted into either root crontab file or postgres crontab file failed
> > either to produce any output or created an empty file caled
> > "old_db_hr9.tgz" in the /backups/hour/ directory..
>
> > 0 9 * * 1-5 postgres pg_dump --format=t old_db >
> > /backups/hour/old_db_hr9.tgz
>
> > 0 18 * * 5 postgres pg_dump --format=t old_db >
> > /backups/week/old_db_friday.tgz
>
> Are you sure you've got the crontab file format correct?  On my machine,
> at least, there's no userid column.

That is a BSD-ism.

--
  Bruce Momjian   http://candle.pha.pa.us
  EnterpriseDB    http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

At 12:28 AM 4/15/06, Bruce Momjian wrote:

>Tom Lane wrote:
> >
> > Are you sure you've got the crontab file format correct?  On my machine,
> > at least, there's no userid column.
>
>That is a BSD-ism.


Not true.  A username column is included in /etc/crontab on both Linux and
BSD systems.

At 02:33 AM 4/17/06, Andrej Ricnik-Bay wrote:

> > >That is a BSD-ism.
> > Not true.  A username column is included in /etc/crontab on both Linux and
> > BSD systems.
>
>Not true.
>
>Not in Dillon's Cron (the one that comes with Slackware) ...
>And there's not even an /etc/crontab file, to begin with.


Thanks, I suppose I have not exposed myself to enough Linux
distros.  Before this morning, I was not aware there were a number of
different cron packages available on Linux.

vixie-cron (used by SuSE) supports the username column in /etc/crontab

On OpenBSD, there is not a /etc/crontab "to begin with"; but create one
(with correct permissions) and it starts working.

I've used MDK and RH, but didn't use /etc/crontab on those systems.

Frank