MariaDB を 10.3 にしようとしたら「A manual upgrade is required.」と言われたので・・・

先日、CentOS 7 の MariaDB を 10.3 にアップデートした話を書きましたが、10.1 → 10.3 の場合は「A manual upgrade is required. 」と言われてしまうことが分かりました。
ちょうど yum でアップデートしようとすると、以下のようなエラーが出ます。

Resolving Dependencies
--> Running transaction check
---> Package MariaDB-server.x86_64 0:10.1.40-1.el7.centos will be updated
---> Package MariaDB-server.x86_64 0:10.3.16-1.el7.centos will be an update
--> Finished Dependency Resolution

Dependencies Resolved

========================================================================================================================================
 Package                          Arch                     Version                                 Repository                      Size
========================================================================================================================================
Updating:
 MariaDB-server                   x86_64                   10.3.16-1.el7.centos                    mariadb-main                    24 M

Transaction Summary
========================================================================================================================================
Upgrade  1 Package

Total download size: 24 M
Is this ok [y/d/N]: y
Downloading packages:
Delta RPMs disabled because /usr/bin/applydeltarpm not installed.
MariaDB-server-10.3.16-1.el7.centos.x86_64.rpm                                                                   |  24 MB  00:00:50
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction

 ******************************************************************
A MySQL or MariaDB server package (MariaDB-server-10.1.40-1.el7.centos.x86_64) is installed.

Upgrading directly from MySQL 10.1 to MariaDB 10.3 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
  files
- 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 MariaDB Foundation
- 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-10.3.16-1.el7.centos.x86_64) scriptlet failed, exit status 1
Error in PREIN scriptlet in rpm package MariaDB-server-10.3.16-1.el7.centos.x86_64
  Verifying  : MariaDB-server-10.3.16-1.el7.centos.x86_64                                                                           1/2
MariaDB-server-10.1.40-1.el7.centos.x86_64 was supposed to be removed but is not!
  Verifying  : MariaDB-server-10.1.40-1.el7.centos.x86_64                                                                           2/2

Failed:
  MariaDB-server.x86_64 0:10.1.40-1.el7.centos                       MariaDB-server.x86_64 0:10.3.16-1.el7.centos

Complete!

† 仕方がないのでマニュアルでアップデート

マニュアルでアップデートと言っても、やることは一旦アンインストールしてから、再インストールするだけです。
とりあえずエラーメッセージに従って、非互換な部分について確認します。
やはり主な問題は sql_mode の部分でしょうか。

Upgrading from MariaDB 10.2 to MariaDB 10.3 - MariaDB Knowledge Base Upgrading from MariaDB 10.1 to MariaDB 10.2 - MariaDB Knowledge Base

ちなみに yum remove しても /var/lib/mysql の下のデータファイルは消えませんが、念のため全データのダンプは取っておきます。
.conf は .rpmsave にリネームされてしまうので、特別な設定を入れている場合にはファイルを復元しておきます。

具体的には以下のような感じでしょうか。

systemctl stop mariadb
yum remove MariaDB-server
yum install MariaDB-server
mv /etc/my.cnf.d/server.conf{,.bak}
mv /etc/my.cnf.d/server.conf{.rpmsave,}
systemctl start mariadb
mysql_upgrade -u root -p