Before starting an upgrade please confirm that you have the backup of MySQL databases and users. Default backup is in the folder /backup/mysql
Verify if MariaDB 10.2 is installed
rpm -qa|grep -i maria|grep "\-10.2."
First you need to change the MariaDB repo and replace it with MariaDB 10.4 repo:
sed -i 's/10.2/10.4/g' /etc/yum.repos.d/mariadb.repo
Second remove MariaDB 10.2 :
systemctl stop mariadb mysql mysqld systemctl disable mariadb rpm --nodeps -ev MariaDB-server
Third Install MariaDB 10.4 :
yum clean all yum -y update "MariaDB-*" yum -y install MariaDB-server systemctl enable mariadb systemctl start mariadb
Fourth you need to upgrade your database tables to the latest version:
mysql_upgrade --force
After upgrade, you can use "mysql" command to verify the MariaDB version running on your server
mysql --version