Vantage Ultimate imports log files created by your network device (firewalls, proxies, routers etc) into a special database file called a storage.
Once log data has been imported into a storage, you can delete or archive the original log files as Vantage Ultimate will use its Storage for analysis and reporting.
Storages are created in the location specified in Tools | Options | Paths. The amount of data stored per day will vary depending on the amount of log file data imported into your WebSpy Vantage storages. Generally speaking, your WebSpy Vantage Storages will be about 80% the size of imported log files (uncompressed log file size).
You can also apply NTFS compression and data deduplication to your WebSpy Vantage Storage folder (Tools | Options | Paths | Storages) to reduce the size of your Storages on disk.
Importing data is done using the Import Logs wizard on the Storages tab. You can then automate log imports using the Import new hits into an existing storage action via Tasks.
You can automate your own data retention policy using the Purge Data from Storage task action which will automatically remove data older than a certain date.
For information on importing log data into a storage, see Importing Log Files