How to see the log information in running docker daemon? -

i use docker on centos, , test docker on mac os x. want see log information when docker run. how find log?

the daemon on boot2docker or centos should have log in /var/log/docker.log.
boot2docker, need in boot2docker session.

(this isn't case: on ubuntu, instance, different: /var/log/upstart/docker.log).

if need see more log, can start daemon -d option.