Or you can use my-large.cnf or my-medium.cnf from /usr/share/mysql to replace /etc/my.cnf. If using my-large.cnf or my-medium.cnf, don't forget always add:
performance-schema=on
default-storage-engine=myisam
skip-innodb
#OpenVZ AIO bug fix
innodb-use-native-aio=0
under '[mysqld]' in /etc/my.cnf.
Better convert storage-engine first with 'sh /script/mysql-convert --engine=myisam'.