There is a registry setting that can be modified for the AFS.log called MaxLogSize. It is measured by events, so if the data value is set to 3000, then it will record 3000 events before overwriting older events.
On the Active Administrator server, go to Start - Run -Regedit
Browse to HKEY_LOCAL_MACHINE\SOFTWARE\Quest\Active Administrator\Settings\AFS
Double click the MaxLogSize and select "Decimal"
You can change the default value from 3000 to a higher or lower number, depending on how many events you want to keep in the AFS.log
Note: The log can grow very large. You can disable AFS logging from within the Active Administrator Server Manager console.
Quest does not provide support for problems that arise from improper modification of the registry. The Windows registry contains information critical to your computer and applications. Make sure you back up the registry before modifying it. For more information on the Windows Registry Editor and how to back up and restore it, refer to Microsoft Article ID 256986 “Description of the Microsoft Windows registry” at Microsoft Support.