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). The file location is 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, on systems that use mysqld_safe to start the server, 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 path 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.