nginxのエラーログ

Note that error_log off does not disable logging - the log will be written to a file named "off". To disable logging, you may use:

error_log /dev/null crit;

• http://wiki.nginx.org/CoreModule#error_log より

オフにできないからレベルを上げたうえで/dev/nullに捨てるのかぁ．