yum update kusanagi -y コマンドでエラーとなります。

sakura vpsのkusanagi8をインストールし、WordPressを公開しようとしています。

https://kusanagi.tokyo/document/kusanagi-init/
上記の手順通り yum update kusanagi -y コマンドを実行すると下記のエラーでストップしてしまうのですが、
どう対処すればよいでしょうか。

One of the configured repositories failed (MariaDB),
 and yum doesn't have enough cached data to continue. At this point the only
 safe thing yum can do is fail. There are a few ways to work "fix" this:

     1. Contact the upstream for the repository and get them to fix the problem.

     2. Reconfigure the baseurl/etc. for the repository, to point to a working
        upstream. This is most often useful if you are using a newer
        distribution release than is supported by the repository (and the
        packages for the previous distribution release still work).

     3. Run the command with the repository temporarily disabled
            yum --disablerepo=mariadb ...

     4. Disable the repository permanently, so yum won't use it by default. Yum
        will then just ignore the repository until you permanently enable it
        again or use --enablerepo for temporary usage:

            yum-config-manager --disable mariadb
        or
            subscription-manager repos --disable=mariadb