Logs in a standard Evergreen installation are located at var/log/evergreen. From there, logs are divided into year/month/day folders. Within a day's folder, there are 4 different types of files:

• activity.log
• gateway.log
• osrfsys.log
• pg.log

With the exception of activity.log, each one of these has multiple files broken into hour chunks. So pg.10.log would be the pg.log for the 10 o'clock hour.