The Database Maintenance page shows the current location, type, and version of your FMAudit Central database:

The Compact/Optimize link shown above can be used to shrink the Microsoft SQL Transaction Log associated with your Central database, thus reclaiming the disk space previously used by the log.

Please note that if your MS SQL installation is not located on the same server as your FMAudit Central website, this Compact/Optimize operation will fail. Microsoft SQL Management Studio can still be used to shrink the log. Please see the Microsoft documentation for more details.