PostgreSQL: Change log file location How can I change the location of the log file in PostgreSQL? Can it be done without stopping the cluster?
re 1) See the chapter "Where to log" in the manual. 

http://www.postgresql.org/docs/current/static/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHERE

You want to change the log_directory property. 

re 2) No, you need to restart Postgres when you change this.