apt-get purge mysql-server
apt-get purge mysql-common
rm -rf /var/log/mysql
rm -rf /var/log/mysql.*
rm -rf /var/lib/mysql
rm -rf /etc/mysql
apt-get install mysql-server –fix-missing –fix-broken
출처: http://aesthetic9.tistory.com/entry/ubuntu에서-mysql-완전삭제-후-재설치 [Doing anything and Doing Nothing]