Cron job to backup the database everynight.

.my.cnf

[mysqldump]
user=root
password=somepass

db_backup.php

# make sure to have a folder ~/db_backup
# and also a .my.cnf in your home folder containing your mysql username and password
$backup_file = "$dbname" . date("Y-m-d-H-i-s") . '.sql';
$command = "mysqldump -u $dbuser $dbname > ~/db_backup/$backup_file";
system($command);