It’s always a good idea to check your config files before you throw them at your live servers. You can parse your MySql my.cnf file by running this at the command line:
mysqld --help --verbose
It’ll pick up you my.cnf file in the default locations and try to interpret all the values, but it won’t actually load them. If anything’s not right it’ll error out with an explanation. If everything’s good you’ll see a table with the configuration that will get loaded.