Here's how it works

Using SharePoint's Extended BLOB Service (EBS) or SQL Server 2008's Remote BLOB Service (RBS) interface, StoragePoint provides a logical layer for SharePoint that allows users to only store metadata and page content within the SQL Server database. Binary Large Objects (BLOBs) are off-loaded to different types of conventional storage space. StoragePoint supports any kind of storage (SAN, DAS, NAS, CAS), including WORM (Write Once Read Many). StoragePoint also support pretty much any cloud storage provider, like Amazon, Rackspace and Windows Azure. Compared to other SharePoint storage externalization and archiving solutions, StoragePoint is unique in that it preserves all SharePoint functionality.

The above described approach comes with the following core benefits:

Performance: For best performance, Microsoft recommends not to exceed an SQL Server database size of 100 GB. Microsoft also states that storing BLOBs larger than 1 MB in SQL Server leads to significantly decreased application performance. Large content databases also cause longer and longer backup windows and offer very little backup granularity.

By reducing the SQL Server database size by about 95%, overall SharePoint performance increases significantly. Pages and documents will download much faster, enhancing the SharePoint user experience. 

Hiearachical Storage Management (HSM): StoragePoint manages where in your network BLOBs are stored. This can be any SAN, NAS, CAS, DAS or cloud drive. To determine which BLOBs go where, you can define simple rules, based on document characteristics like "content type," "document type," "SharePoint Site," etc.

Archiving: Documents of a specific age can be moved to lower-tier storage and eventually even to the cloud.

Easy Backups: Backups are significantly faster, as they are much more granular, than simply backing up a content database.

Storage Cost: Moving less-important data off the enterprise SAN and to lower-tier storage space or even the cloud leads to signficant cost savings.