install mariadb-server
sudo apt-get install software-properties-common
sudo apt-key adv --fetch-keys 'https://mariadb.org/mariadb_release_signing_key.asc'
sudo add-apt-repository 'deb [arch=amd64,arm64,ppc64el] https://mirrors.ustc.edu.cn/mariadb/repo/10.5/ubuntu focal main'
安装：
sudo apt update
sudo apt install mariadb-server
configuration
切换到root用户执行：
mariadb-secure-installation
即可设置密码。