Upgrade MariaDB 10.0.x to MariaDB 10.1.x on Centos (yum)

Here are steps you should do to upgrade your older MariaDB 10.1.x to the latest version of MariaDB 10.1.x.

0. Prepare for upgrade 

- make sure no traffic is coming to database server
- make backup of configuration files  /etc/my.cnf*
- backup all your databases running on the server in case something goes wrong during upgrade 

1. Update yum repository config located in /etc/yum.repos.d/MariaDB.repo with new content. You can generate your config file here: https://downloads.mariadb.org/mariadb/repositories/

e.g. in our case the content looks like:

name=MariaDB 10.0 CentOS repository list - created 2015-02-06 13:47 UTC
humanname=MariaDB 10.0 CentOS repository list - created 2015-02-06 13:47 UTC

And we will replace it with new config:

name = MariaDB
baseurl = https://yum.mariadb.org/10.1/centos6-amd64


2. Stop mysql service

service mysql stop

3. Update MariaDB installation files

yum update

In case update will fail with message like this, you need to install MariaDB manually:

A MySQL or MariaDB server package (MariaDB-server-10.0.21-1.el6.x86_64) is installed.

Upgrading directly from MySQL 10.0 to MariaDB 10.1 may not
be safe in all cases.  A manual dump and restore using mysqldump is
recommended.  It is important to review the MariaDB manual's Upgrading
section for version-specific incompatibilities.

A manual upgrade is required.
- Ensure that you have a complete, working backup of your data and my.cnf
- Shut down the MySQL server cleanly
- Remove the existing MySQL packages.  Usually this command will
  list the packages you should remove:
  rpm -qa | grep -i '^mysql-'

  You may choose to use 'rpm --nodeps -ev <package-name>' to remove
  the package which contains the mysqlclient shared library.  The
  library will be reinstalled by the MariaDB-shared package.
- Install the new MariaDB packages supplied by Monty Program AB
- Ensure that the MariaDB server is started
- Run the 'mysql_upgrade' program

This is a brief description of the upgrade process.  Important details
can be found in the MariaDB manual, in the Upgrading section.
error: %pre(MariaDB-server-10.1.8-1.el6.x86_64) scriptlet failed, exit status 1

Error in PREIN scriptlet in rpm package MariaDB-server-10.1.8-1.el6.x86_64
error:   install: %pre scriptlet failed (2), skipping MariaDB-server-10.1.8-1.el6
  Verifying  : MariaDB-server-10.1.8-1.el6.x86_64                                                                                                                                   MariaDB-server-10.0.21-1.el6.x86_64 was supposed to be removed but is not!

  Verifying  : MariaDB-server-10.0.21-1.el6.x86_64                                                                                                                                  Failed:
  MariaDB-server.x86_64 0:10.0.21-1.el6                                                      MariaDB-server.x86_64 0:10.1.8-1.el6                                                   Complete!

In our case I have found all packages related to Mariadb with command 

rpm -qa | grep -i '^MariaDB'

And removed them with commands like:

yum remove MariaDB-server

And than installed MariaDB server with command:

yum install MariaDB-server

Update configuration files in /etc/my.cnf.d/ directory. Some files could be overwritten during the installation of new MariaDB version.

4. start mysql service

service mysql start

5. run mysql upgrade

It could take a while until all upgrade steps are finished (6 steps), especially if you have hundreds of databases and tables on your server. Don't forget, that the mysql process has to be running before you can start upgrade.

mysql_upgrade -u root -p

6. Post-upgrade steps

- Once the mysql upgrade finished, you should review mysql error log if all works as expected.
- Review my.cnf for new configuration settings - new version comes with ton of new features and configuration options - why not to profit from them.