5.4.2.2 Error Logging on Unix and Unix-Like Systems
On Unix and Unix-like systems, mysqld uses the --log-error
option to determine whether mysqld writes the error log to the console or a file, and, if to a file, the file name:
If
--log-error
is not given, mysqld writes the error log to the console.If
--log-error
is given without naming a file, mysqld writes the error log to a file named
in the data directory.host_name
.errIf
--log-error
is given to name a file, mysqld writes the error log to that file (with an.err
suffix added if the name has no suffix), located under the data directory unless an absolute path name is given to specify a different location.If
--log-error
is given in an option file in a[mysqld]
,[server]
, or[mysqld_safe]
section, mysqld_safe finds and uses the option, and passes it to mysqld.
It is common for Yum or APT package installations to configure an error log file location under /var/log
with an option like log-error=/var/log/mysqld.log
in a server configuration file. Removing the file name from the option causes the
file in the data directory to be used. host_name
.err
If the server writes the error log to the console, it sets the log_error
system variable to stderr
. Otherwise, the server writes the error log to a file and sets log_error
to the file name.