Código PHP:
// Mysql Database Information:
$db_name = "name";
$db_username = "username";
$db_password = "password";
$backup_db_as = "elnombre.gz";
$backupcommand = "mysqldump --add-drop-table --add-locks -u$db_username -p$db_password $db_name | gzip > $backup_db_as";
passthru( "$backupcommand", $error );