/root = OS & AirWave codebase
/usr = running code
/var = logs, database (includes reports), graphs, and backups
-- MC compiles data collected from watched AMPs for summary view
-- MC reports will either go off local MC db or be pulled from the watched AMPs depending on the data granularity of the report
Ideally, it will be installed as a single partition, but if you must pull a partition off server - it should be the /var partition which usage varies based on number of watched AMPs and number of reports (and frequency reports are run).