Hello, there is MariaDB installed using the apt command on your server. It is recommended that you deal with it.
Make a snapshot backup of the server before operation.

apt remove mariadb*
cd /etc/systemd/system/
rm mysqld.service mysql.service
systemctl daemon-reload
/etc/init.d/mysqld start

aaP_hazardtrader968

    aaPanel_Kern root@webserver1:~# apt remove mariadb*
    e
    systemctl daemon-reload
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    Note, selecting 'mariadb-rocksdb-engine-10.2' for glob 'mariadb'
    Note, selecting 'mariadb-rocksdb-engine-10.3' for glob 'mariadb
    '
    Note, selecting 'mariadb-test' for glob 'mariadb'
    Note, selecting 'mariadb-test-data-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-testsuite-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-testsuite-10.3' for glob 'mariadb
    '
    Note, selecting 'mariadb-test-data' for glob 'mariadb'
    Note, selecting 'mariadb-plugin-cracklib-password-check' for glob 'mariadb
    '
    Note, selecting 'mariadb-test-5.5' for glob 'mariadb'
    Note, selecting 'mariadb-common' for glob 'mariadb
    '
    Note, selecting 'mariadb-plugin-connect' for glob 'mariadb'
    Note, selecting 'mariadb-server-core-5.5' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-5.1' for glob 'mariadb'
    Note, selecting 'mariadb-server-5.2' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-5.3' for glob 'mariadb'
    Note, selecting 'mariadb-server-5.5' for glob 'mariadb
    '
    Note, selecting 'mariadb-tokudb-engine-5.5' for glob 'mariadb'
    Note, selecting 'mariadb-server-core-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-core-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-server-core-10.2' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-core-10.3' for glob 'mariadb'
    Note, selecting 'mariadb-connect-engine-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-connect-engine-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-galera-server' for glob 'mariadb
    '
    Note, selecting 'mariadb-backup' for glob 'mariadb'
    Note, selecting 'mariadb-client-5.5' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-10.0' for glob 'mariadb'
    Note, selecting 'mariadb-server-10.1' for glob 'mariadb
    '
    Note, selecting 'mariadb-server-10.2' for glob 'mariadb'
    Note, selecting 'mariadb-server-10.3' for glob 'mariadb
    '
    Note, selecting 'mariadb-plugin-oqgraph' for glob 'mariadb'
    Note, selecting 'mariadb-plugin-gssapi-client' for glob 'mariadb
    '
    Note, selecting 'mariadb-plugin-spider' for glob 'mariadb'
    Note, selecting 'mariadb-galera-server-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-plugin-rocksdb' for glob 'mariadb'
    Note, selecting 'mariadb-plugin-gssapi-server' for glob 'mariadb
    '
    Note, selecting 'mariadb-plugin-tokudb' for glob 'mariadb'
    Note, selecting 'mariadb-client-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-client-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-client-10.2' for glob 'mariadb
    '
    Note, selecting 'mariadb-client-10.3' for glob 'mariadb'
    Note, selecting 'mariadb-server' for glob 'mariadb
    '
    Note, selecting 'mariadb-tokudb-engine-10.0' for glob 'mariadb'
    Note, selecting 'mariadb-tokudb-engine-10.1' for glob 'mariadb
    '
    Note, selecting 'mariadb-client-core-10.0' for glob 'mariadb'
    Note, selecting 'mariadb-client-core-10.1' for glob 'mariadb
    '
    Note, selecting 'mariadb-client-core-10.2' for glob 'mariadb'
    Note, selecting 'mariadb-client-core-10.3' for glob 'mariadb
    '
    Note, selecting 'mariadb-client' for glob 'mariadb'
    Note, selecting 'mariadb-test-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-test-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-oqgraph-engine-10.0' for glob 'mariadb
    '
    Note, selecting 'mariadb-oqgraph-engine-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-galera-server-5.5' for glob 'mariadb
    '
    Note, selecting 'mariadb-client-core-5.5' for glob 'mariadb'
    Note, selecting 'mariadb-gssapi-server-10.1' for glob 'mariadb
    '
    Note, selecting 'mariadb-gssapi-server-10.2' for glob 'mariadb'
    Note, selecting 'mariadb-gssapi-client-10.1' for glob 'mariadb
    '
    Note, selecting 'mariadb-gssapi-client-10.2' for glob 'mariadb'
    Note, selecting 'mariadb-plugin-mroonga' for glob 'mariadb
    '
    Note, selecting 'mariadb-backup-10.1' for glob 'mariadb'
    Note, selecting 'mariadb-backup-10.2' for glob 'mariadb
    '
    Package 'mariadb-client-10.1' is not installed, so not removed
    Package 'mariadb-client-core-10.1' is not installed, so not removed
    Package 'mariadb-server-5.5' is not installed, so not removed
    Package 'mariadb-server-10.1' is not installed, so not removed
    Package 'mariadb-server-core-10.1' is not installed, so not removed
    Package 'mariadb-galera-server-10.0' is not installed, so not removed
    Package 'mariadb-galera-server-5.5' is not installed, so not removed
    Package 'mariadb-server-10.0' is not installed, so not removed
    Package 'mariadb-server-5.1' is not installed, so not removed
    Package 'mariadb-server-5.2' is not installed, so not removed
    Package 'mariadb-server-5.3' is not installed, so not removed
    Package 'mariadb-backup-10.1' is not installed, so not removed
    Package 'mariadb-backup-10.2' is not installed, so not removed
    Package 'mariadb-client-10.0' is not installed, so not removed
    Package 'mariadb-client-10.2' is not installed, so not removed
    Package 'mariadb-client-5.5' is not installed, so not removed
    Package 'mariadb-client-core-10.0' is not installed, so not removed
    Package 'mariadb-client-core-10.2' is not installed, so not removed
    Package 'mariadb-client-core-5.5' is not installed, so not removed
    Package 'mariadb-connect-engine-10.0' is not installed, so not removed
    Package 'mariadb-connect-engine-10.1' is not installed, so not removed
    Package 'mariadb-gssapi-client-10.1' is not installed, so not removed
    Package 'mariadb-gssapi-client-10.2' is not installed, so not removed
    Package 'mariadb-gssapi-server-10.1' is not installed, so not removed
    Package 'mariadb-gssapi-server-10.2' is not installed, so not removed
    Package 'mariadb-oqgraph-engine-10.0' is not installed, so not removed
    Package 'mariadb-oqgraph-engine-10.1' is not installed, so not removed
    Package 'mariadb-rocksdb-engine-10.2' is not installed, so not removed
    Package 'mariadb-rocksdb-engine-10.3' is not installed, so not removed
    Package 'mariadb-tokudb-engine-10.0' is not installed, so not removed
    Package 'mariadb-tokudb-engine-10.1' is not installed, so not removed
    Package 'mariadb-tokudb-engine-5.5' is not installed, so not removed
    Package 'mariadb-galera-server' is not installed, so not removed
    Package 'mariadb-server-10.2' is not installed, so not removed
    Package 'mariadb-server-core-10.0' is not installed, so not removed
    Package 'mariadb-server-core-10.2' is not installed, so not removed
    Package 'mariadb-server-core-5.5' is not installed, so not removed
    Package 'mariadb-test-10.0' is not installed, so not removed
    Package 'mariadb-test-10.1' is not installed, so not removed
    Package 'mariadb-test-5.5' is not installed, so not removed
    Package 'mariadb-test-data-10.0' is not installed, so not removed
    Package 'mariadb-testsuite-10.1' is not installed, so not removed
    Package 'mariadb-testsuite-10.3' is not installed, so not removed
    The following packages were automatically installed and are no longer required:
    cracklib-runtime galera-3 libcgi-fast-perl libcgi-pm-perl libconfig-inifiles-perl libcrack2 libdbd-mysql-perl
    libdbi-perl libencode-locale-perl libfcgi-perl libgflags2.2 libhtml-parser-perl libhtml-tagset-perl
    libhtml-template-perl libhttp-date-perl libhttp-message-perl libio-html-perl libjudydebian1 liblwp-mediatypes-perl
    libodbc1 odbcinst odbcinst1debian2 python3-mysqldb rcs rocksdb-tools unixodbc
    Use 'apt autoremove' to remove them.
    The following packages will be REMOVED:
    libmariadb-dev libmariadb3 libmariadbclient-dev mariadb-backup mariadb-client mariadb-client-10.3
    mariadb-client-core-10.3 mariadb-common mariadb-plugin-connect mariadb-plugin-cracklib-password-check
    mariadb-plugin-gssapi-client mariadb-plugin-gssapi-server mariadb-plugin-mroonga mariadb-plugin-oqgraph
    mariadb-plugin-rocksdb mariadb-plugin-spider mariadb-plugin-tokudb mariadb-server mariadb-server-10.3
    mariadb-server-core-10.3 mariadb-test mariadb-test-data
    0 upgraded, 0 newly installed, 22 to remove and 0 not upgraded.
    After this operation, 601 MB disk space will be freed.
    Do you want to continue? [Y/n] Abort.
    root@webserver1:~# systemctl daemon-reload
    root@webserver1:~# /etc/init.d/mysqld start
    Starting mysqld (via systemctl): mysqld.serviceJob for mariadb.service failed because the control process exited with error code.
    See "systemctl status mariadb.service" and "journalctl -xe" for details.
    failed!

      aaP_hazardtrader968

      cd /etc/systemd/system/
      rm mysqld.service mysql.service
      systemctl daemon-reload
      /etc/init.d/mysqld start

        aaPanel_Kern root@webserver1:~# cd /etc/systemd/system/
        root@webserver1:/etc/systemd/system# rm mysqld.service mysql.service
        root@webserver1:/etc/systemd/system# systemctl daemon-reload
        troot@webserver1:/etc/systemd/system# /etc/init.d/mysqld start
        Starting mysqld (via systemctl): mysqld.serviceJob for mysqld.service failed because the control process exited with error code.
        See "systemctl status mysqld.service" and "journalctl -xe" for details.
        failed!
        root@webserver1:/etc/systemd/system#

          aaPanel_Kern Please send your email ID, I am tired of solving this problem for the last 5 days. Give me your email ID. I will send you the username password of your Aa panel. Please fix it and give it to me.

            It is recommended that you tell us the operating system you are using and the mysql version installed.
            If you install mariaDB, it is recommended that you change it to mysql
            And check the log file /tmp/panelExec.log

            aaP_hazardtrader968

              Hi, can you give us your aapanel information? The server makes a snapshot backup first, if possible, please send it to kern@aapanel.com.
              It is recommended to fill in the following
              Post link:
              SSH IP address, account password and port:
              aapanel login link address and account password:
              Detailed problem description:

              No post link will not be able to know which user's information is, and the problem will not be processed

              aaP_hazardtrader968

                aaP_hazardtrader968

                Hello, been asking you to check the logs and this is why.
                There is currently a database running. Stop installation!
                If you are unable to provide more information, it is recommended that you handle it yourself.

                aaP_hazardtrader968