Your rules shouldn't have any impact on usr\local unless they're generating errors.
In addition to what wolram said, you can see the manager log without needing the unique root password. In your CMC menu, go to the manager section and run the "watchlog" command. You'll also be able to get a dump of the manager logs by running the debug command and providing a CIFS share. The LEM logs are usually pretty human friendly, so if there are any errors or warnings, they'll leap out pretty quick. LEM rotates those logs on a schedule, so as soon as any issues are resolved, you should see disk usage begin to drop off.