Para remover o MySQL por completo: 

sudo apt remove --purge mysql-server
sudo apt purge mysql-server
sudo apt autoremove
sudo apt autoclean
sudo apt remove dbconfig-mysql
sudo systemctl stop mysql
sudo apt purge mysql-server mysql-client mysql-common mysql-server-core-* mysql-client-core-*
sudo rm -rf /etc/mysql /var/lib/mysql /var/log/mysql
sudo apt autoremove
sudo apt autoclean

Para iniciar a instalação do MariaDB faça:

$ sudo ln -s /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable/
$ sudo apparmor_parser -R /etc/apparmor.d/usr.sbin.mysqld 

sudo dpkg --configure mariadb-server

$ sudo systemctl stop apparmor.service
$ sudo update-rc.d -f apparmor remove

$ sudo apt-get remove --purge mysql-server mysql-client mysql-common
$ sudo apt-get autoremove
$ sudo apt-get autoclean
$ sudo apt-get install mariadb-server

$ sudo systemctl start apparmor.service
$ sudo update-rc.d apparmor defaults

Fontes:
https://www.digitalocean.com/community/tutorials/how-to-install-mariadb-on-ubuntu-20-04-pt

https://www.digitalocean.com/community/questions/completely-uninstall-mysql-server

https://mariadb.com/kb/en/the-community-mariadb-troubles-only-running-after-reboot-times-out-when-try/

Comentários