[SOLVED] Shell script doesn't run on cron (otherwise it works)

kalashari · 02-17-2012, 12:25 PM

Hi all,

So I have a VPS where I have the following shell script meant to run every 24 hours (it takes all the databases and certain folders and rsync them to remote server):

backup.sh looks like this:

Code:

#!/bin/sh

# Directory that holds the database backup
DB_BACKUP_DIR=/home/db_backup

# Directories to rsync
DIRS="/var/www $DB_BACKUP_DIR /etc/apache2"

DB_ARCHIVE="$DB_BACKUP_DIR/db_backup_$(date +%a).gz"

/usr/bin/mysqldump --opt -uroot -pmypass --all-databases | gzip > $DB_ARCHIVE

for DIR in $DIRS
do
/usr/local/bin/rsync -rzvt $DIR user@remote-server
done

rm $DB_ARCHIVE

And for the crontab entry I have:

Code:

20 6 * * * /bin/sh /root/backup.sh

The shell script will run normal if I run it from the shell, but it doesn't run from cron. Does anyone have any idea what could be wrong here?

I have this same script on a different VPS and when ran from cron it works ok. But on this VPS it won't work.

Thanks in advance!

TB0ne · 02-17-2012, 12:28 PM

Quote:

Originally Posted by kalashari

Hi all,
So I have a VPS where I have the following shell script meant to run every 24 hours (it takes all the databases and certain folders and rsync them to remote server) backup.sh looks like this:

The shell script will run normal if I run it from the shell, but it doesn't run from cron. Does anyone have any idea what could be wrong here? I have this same script on a different VPS and when ran from cron it works ok. But on this VPS it won't work.
Thanks in advance!

The only possible thing I can see is that you're not putting in the whole path to gzip. Cron may (or may not) supply a path to that command when it runs, depending on the user the job is running as. So, it'll try, the pipe command will fail, and the script will exit.

Try specifying it as "/usr/bin/gzip", or whatever it is on your system. Type in "which gzip" to find out.

kalashari · 02-17-2012, 12:32 PM

I tried that as well. Didn't work.

Also here's my system $PATH variable: /usr/java/jdk/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

repo · 02-17-2012, 12:42 PM

Do you get any errors?
Cron will sent a mail to the owner of the cronjob in case of problems.

Kind regards

Guttorm · 02-17-2012, 12:42 PM

Hi

It could help if you use this in the beginning of the script

#!/bin/bash -x

Also, remove the /bin/sh in the crontab, and set the execute bit on the script with chmod. You will then run the script in bash debug mode, with lots of lines explaining what happens. And because cron usually sends output as mail, you should get an email with debug information.

kalashari · 02-17-2012, 01:17 PM

Cheers guys! Turns out, I had a problem with "permission denied" when rsync-ing (due to the other VPS overwritten ssh keys). So I had to append ssh key for this VPS so that backup scripts on both VPS work.

So basically script worked fine and cron worked fine. I just wasn't able to see errors! Because I had set MAILTO="" in my crontab.

Glad I opened the topic here. Looks like a really nice community!

TB0ne · 02-17-2012, 01:50 PM

Quote:

Originally Posted by kalashari

Cheers guys! Turns out, I had a problem with "permission denied" when rsync-ing (due to the other VPS overwritten ssh keys). So I had to append ssh key for this VPS so that backup scripts on both VPS work.

So basically script worked fine and cron worked fine. I just wasn't able to see errors! Because I had set MAILTO="" in my crontab.

Glad I opened the topic here. Looks like a really nice community!

Thanks for posting the solution...so many folks never say anything, and don't share their knowledge.