There is no such thing as 'MySQL in Plesk'. Plesk normally just installs the MySQL packages that come with your distribution. If your current MySQL installation doesn't support the Archive storage engine, then you'll have to find or create a compatible package that does support it. I don't know what OS you are running, but apparently the stock CentOS 5 MySQL packages don't support the Archive storage engine (according to the output of SHOW ENGINES).
If you need to know where they are stored (do you?) you can ask your package manager. On an RPM-based distribution you'd run 'rpm -ql mysql-server' for a list of files installed by the mysql-server package.
If you need to know where they are stored (do you?) you can ask your package manager. On an RPM-based distribution you'd run 'rpm -ql mysql-server' for a list of files installed by the mysql-server package.
I'm not sure to what files or statements you are referring exactly, but I believe there is no Plesk-specific configuration in our MySQL configuration files.
Ok, I'm really scared to recomplie MySQL. Maybe Atomic Rocket Turtle will have a package for me.