Quota and File Sentinel - license - 1 TB capacity

Disk space is your server's most expensive subsystem. By enforcing disk space limits on directories, shares and servers, you can control how much your users consume; manage what data and/or file types your users put on your servers and storage devices; get real-time data on storage performance and load. NTP Software Quota & File Sentinel enables you to enforce appropriate usage policies, so you can preserve system performance and availability for everyone.

NTP Software's Quota & File Sentinel (QFS) has several enhancements that will significantly extend the ability of administrators to manage complex storage environments. The primary focus of QFS version is to provide greater control, more thorough reporting, and improved flexibility.