MySQL backup cron job not executing correctly

lakridserne · 03-02-2011, 04:15 AM

Hi,

I own a CentOS 5 VPS. I typed crontab -e, and then I added the following line to automatically have my server backup mysql

0 * * * * mysqldump -u root -p password --all-databases | gzip > /home/dbbackup/database_`date '+%m-%d-%Y_%H'`.sql.gz

When I go in and look, it doesn't place any files in /home/dbbackup. When I run

mysqldump -u root -p password --all-databases | gzip > /home/dbbackup/database_`date '+%m-%d-%Y_%H'`.sql.gz

it'll place the files as it should.

What am I doing wrong?

Thanks a lot in advance.

kuyalfinator · 03-02-2011, 04:21 AM

CRON is tricky. Its picky in a the sense on how it uses syntax. First, look at the cron manual.

$man cron

Next, make sure the command your trying to type works. In testing cron, try a simple script for just getting a small mysql query.

$mysql> select name from myTable > TestMysqlCron

jlinkels · 03-02-2011, 04:38 AM

Piping ('|') doesn't work in cron because the interpreter sees the first part as the cron command and the part behind the pipe as a parameter, not as a second command to execute.

In order for this (a piped command) to work, create a separate script and call this script from cron.

jlinkels

lakridserne · 03-02-2011, 09:10 AM

Thanks. This did it.

Quote:

Originally Posted by jlinkels

Piping ('|') doesn't work in cron because the interpreter sees the first part as the cron command and the part behind the pipe as a parameter, not as a second command to execute.

In order for this (a piped command) to work, create a separate script and call this script from cron.

jlinkels