steps by steps upgrade mariadb 5.x to 10.2 in centos 7

Step 1  

Backup databases and data directory

mysqldump -u root -p -R -E --all-databases > /tmp/all-database-backup.sql

Check backup *.sql

    ll /tmp/

Stop mariadb server

systemctl stop mariadb.service

Copy the databases directory in a separate

cp -ar /var/lib/mysql/ /var/lib/mysql.bak

Note : In case of failure of the upgrade you can use one of the above copies to restore your databases.

Step 2

Add the MariaDB Repository.

echo "[mariadb]

name = MariaDB

baseurl = http://yum.mariadb.org/10.2/centos7-amd64

gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB

gpgcheck=1" >> /etc/yum.repos.d/MariaDB10.2.repo

OR

vi /etc/yum.repos.d/MariaDB10.2.repo

Add the following text in it:

[mariadb]

name = MariaDB

baseurl = http://yum.mariadb.org/10.2/centos7-amd64

gpgkey=https://yum.mariadb.org/RPM-GPG-KEY-MariaDB

gpgcheck=1

Step 3

Remove MariaDB 5.5

    rpm -qa | grep mariadb*

rpm -e --nodeps mariadb-server-5.5.50-1.el7_2.x86_64 mariadb-devel-5.5.50-1.el7_2.x86_64 mariadb-libs-5.5.50-1.el7_2.x86_64 mariadb-5.5.50-1.el7_2.x86_64

Step 4

Installing MariaDB 10.2

yum -y install MariaDB-server

Start the MariaDB service with:

systemctl start mariadb

Enable MariaDB to automatically start after system boot

systemctl enable mariadb

Finally run the upgrade command to upgrade MariaDB with:

mysql_upgrade

To verify that the upgrade was successful, run the following command:

mysql -V