cd /usr/local/directadmin/custombuild
./build set mysql 5.5
./build set mysql_inst mysql
./build update
./build mysql
./build set mysql 5.7
./build update
./build mysql




If you wish to upgrade MySQL to 5.5, do it in increments, upgrading 10.6 to the next version released, and going up until you reach 5.5.

Remove MYSQL:

perl -pi -e 's/mysqld=ON/mysqld=OFF/' /usr/local/directadmin/data/admin/services.status
service mysqld stop
mv /var/lib/mysql /var/lib/mysql.old