Could not use /var/log/mysqld-slow.log for logging (error 13 - Permission denied).

configuration file /etc/my.cnf:

log_error = /var/log/mysqld.log

slow_query_log_file = /var/log/mysqld-slow.log

if I delete both of these files and restart mysqld service - behavior is different:

log file /var/log/mysqld.log is created with permissions 0640 and ownetr:group mysql:mysql.

log file /var/log/mysqld-slow.log not created and MySQL write warning message to log file /var/log/mysqld.log:

Could not use /var/log/mysqld-slow.log for logging (error 13 - Permission denied). Turning logging off for the server process. To turn it on again: fix the cause, then either restart the query logging by using "SET GLOBAL SLOW_QUERY_LOG=ON" or restart the MySQL server.

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If MySQL server can create /var/log/mysqld.log log file on the startup, when this file is absent, but don`t want to create log file /var/log/mysqld-slow.log ?

Looks like this is bug/inconsistency in the MySQL.

Can you please fix this bug and automatically create both of these files on mysqld startup?

Workaround for this bug:

$ cat /etc/systemd/system/mysqld.service.d/override.conf

[Service]
LimitNOFILE = 8388608

ExecStartPre=+touch /var/log/mysqld-slow.log
ExecStartPre=+chown mysql:mysql /var/log/mysqld-slow.log
ExecStartPre=+chmod 0600 /var/log/mysqld-slow.log

ExecStartPre=+touch /var/log/mysqld.log
ExecStartPre=+chown mysql:mysql /var/log/mysqld.log
ExecStartPre=+chmod 0600 /var/log/mysqld.log

ExecStartPre=+/usr/bin/mysqld_pre_systemd