cron doesn't have permission?

[uprightdog]

I have a php script that creates a dump of MySQL and mails it out for back-up purposes. This script works fine when run through a browser, but unfortunately the MySQL dump aspect of it fails when run through a cron job (other parts of the script work, just the dump fails). I'm sure this is a permissions thing - cron doesn't have permission to do the MySQL command - but how do I fix it?

This is the command:

/usr/bin/mysqldump -umyusername -pmypassword --databases mydatabase | gzip > /var/www/vhosts/mydomain/httpdocs/backups/backup.sql.gz

[thisisit3]

A typical problem with cron jobs is the PATH environment.

For example, when you execute the command manually, it takes the existing PATH environment so all commands work fine.

BUT, when cron runs the command, it has its own limited environment which has been set in the crontab. The default contains a few basic paths, thus many script commands fail.

So, first check that you are using full paths, for example your "mysqldump" has the full path but the "gzip" command doesn't.

As a side note, i have two suggestions:

1) use bzip2, its much better than the old gzip (its the best 'zip' really)

2) use the "--opt" parameter when doing sql backups, it produces a portable backup that contains all the database details needed to restore the database, "man mysqldump" for more information about it.

[uprightdog]

The paths seem fine.

Any other ideas?

[thisisit3]

are you sure the command is correct and it runs fine when executed via command line?

you could add some debug output, save stderr to a text file and read it to see what the error is.

usually, cron grabs the stderr/stdout and emails it to you.