I'm currently utilizing: Nginx + PHP-FPM (7.1.8) + Memcahce + Redis + MariaDb 10.2.7
First before you do anything make a backup of your current database:
mysqldump -u root -p --all-databases > database-backup.sql
Next stop and uninstall the current mariadb service:
# service mysql stop
$ yum remove mysql* mariadb*
$ yum clean all
Also make a backup of your etc/my.cnf file before you do this. (you can always get the default one from /usr/share/mysql)
Create a file in /etc/yum.repos.d/MariaDB.repo then copy and paste the code below inside it.
name = MariaDB
baseurl = http://yum.mariadb.org/10.2/centos7-amd64
Save then install mariadb 10.2:
$ yum install MariaDB-server MariaDB-client
then start the mysql service:
# service mysql start
then run and upgrade
# mysql_upgrade -u root -p
restore your my.cnf you made a backup of or use one of the examples in the directory i mentioned above. (if you happen to use the example, remove the
innodb_additional_mem_pool_size line as it's no longer being used)
Your mysql service has now been upgraded to 10.2 without issue. The Mysql area will be able to read the config file.
Now you may have noticed that during the uninstall that postfix was also uninstalled along with mariadb 5.5. This indeed happened however luckily it created a backup for the main, virtual and master configuration before uninstallation.
go to your Webmin CP -> Servers -> Postfix Mail Server It will say that it's not installed, click the install button for it to reinstall now go back to "Postfix Mail Server" settings and go to "Edit Config Files"
in the dropdown go to main.rpmsave, virtual.rpmsave and master.rpmsave and copy/paste each one to their respective default file.
If you also installed dkim-milter, it would have also created a backup file of dkim-fliter.conf.rpmsave so just apply the same thing there (i assume there's not in house editor so you'll have to restore via ssh)