logging bestpractice in production

In production i wanted to reduce the loglevel, but when i set the
log_level to :warn, rails stops logging the request, params.
completion time etc.

The code below works, but had some questions:
1) is it ok to dup the logger object
2) i am using BufferedLogger, can the logs be shuffled
eg. i have two processes, P1 and P2

and P1 logs:
hello i am P1
the uptime is 1000

and P2 logs;
hello i am P2
the uptime is 250

and the actual log is:
hello i am P1
hello i am P2
the uptime is 1000
the uptime is 250

3) i am using passenger - will it make a difference in (2).
Does it make a difference to logging if i am using mongrel, jruby or

Logging config:

# See everything in the log (default is :info)
# But this also stops logging of the request by rails
config.log_level = :warn

config.logger =
config.logger.level = ActiveSupport::BufferedLogger::WARN

# is dup'ing the logger object correct/bestpractice
# will the logs be in order or can they be shuffled - i am using
passenger - will it make a difference?
config.action_controller.logger = config.logger.dup
config.action_controller.logger.level =