To specify the filename of the MySQL error log the following command line option can be used with the mysqld and mysqld_safe commands.
--log-error=/path/to/filename
Alternatively you can specify the MySQL error log using the MySQL Configuration File my.cnf, for example:
[mysqld] log-error=/path/to/filename [mysqld_safe] log-error=/path/to/filename
If unspecified, the MySQL error log will be found in the MySQL data directory of the instance and will have the filename hostname.err
Determining value of log-error
You can determine the current error log for a running MySQL instance with the log_error system variable. For example with the SHOW command or the INFORMATION_SCHEMA:
mysql> SHOW GLOBAL VARIABLES LIKE 'log_error';
+---------------+----------------------------+
| Variable_name | Value |
+---------------+----------------------------+
| log_error | /opt/mysql51/log/error.log |
+---------------+----------------------------+
mysql> SELECT variable_value FROM INFORMATION_SCHEMA.GLOBAL_VARIABLES
-> WHERE variable_name='log_error';
+----------------------------+
| variable_value |
+----------------------------+
| /opt/mysql51/log/error.log |
+----------------------------+
Additional References
- MySQL Reference Manual – Error Log
- MySQL Reference Manual – Server options
- Blog Post “Monitoring MySQL – The Error Log”
Related Options
--syslog--skip-syslog--log-warnings--console
