MySQL Error log Configuration for MySQL on Windows & MySQL on Linux - MySQL DBA Tutorial

What is Error Logging in MySQL Server and How to Enable in Windows and Linux

MySQL Error log Configuration  for MySQL on Windows & MySQL on Linux
MySQL Error logging information stored the information for start, shutdown and restarting of MySQL Server. The default location for error log if the MySQL Server instantiated on Windows is data directory. To check the location for Error log on windows you can go to my.ini file and then look for error-log. By Default the name of error log is "HostName.err".

If the MySQL Server is installed on Linux, then you will be able to find the mysqld.log file under /var/log/ directory.
If you want to check the location of mysqld.log file , you can go to /etc/my.cnf file and look for error-log.

MySQL Logging Tutorial - Enable MySQL Error Logging in Windows and Linux