Em link :
The available log levels are:
:debug
,:info
,:warn
,:error
,:fatal
, and:unknown
, corresponding to the log level numbers from 0 up to 5 respectively. To change the default log level, useconfig.log_level = :warn # In any environment initializer, or Rails.logger.level = 0 # at any time
This is useful when you want to log under development or staging, but you don't want to flood your production log with unnecessary information.
The default Rails log level is
debug
in all environments