##upgrade mysql engine from 5.5 to 5.6 in directadmin
https://help.directadmin.com/item.php?id=240cd /usr/local/directadmin/custombuild
./build set mysql 5.5
./build set mysql_inst mysql
./build set mysql_backup yes
./build update
./build mysql
Where mysql can be 5.1, 5.5, or 5.6.
A full raw sql backup will be run prior to the upgrade if you have mysql_backup=yes set. It goes without saying, always make backups, either with this tool, or with other means.
After the mysql update, always recompile php.
./build php n