Plesk update fails with the following error:
CONFIG_TEXT: Trying to backup MySQL database...
ERROR while trying to backup MySQL database
Check the error reason(see log file: /var/log/plesk/install/plesk_17.5.3_installation.log), fix and try again
A similar error can be found in
CONFIG_TEXT: Trying to start service mariadb... failed
systemd: Starting MariaDB database server...
systemd: mariadb.service: main process exited, code=exited, status=1/FAILURE
systemd: Failed to start MariaDB database server.
systemd: Unit mariadb.service entered failed state.
systemd: mariadb.service failed.
Some problems are found during start service mariadb(see log file: /var/log/plesk/psa_service.log)
MySQL was installed instead of MariaDB:
# service mysql status | head -n1
● mysql.service - MySQL Community Server
/usr/lib/systemd/system/mariadb.serviceexists on the server:
# file /usr/lib/systemd/system/mariadb.service
/usr/lib/systemd/system/mariadb.service: ASCII text
MariaDB service files were not removed completely.
Connect to the server via SSH;
Move MariaDB service file to the another directory:
# mv /usr/lib/systemd/system/mariadb.service /root/