The concept behind WatchDISK is simple: Take a snapshot of the sizes of directories (not the content itself, just the sizes) and store that snapshot in a database. Later, take another snapshot. By comparing the snapshots you can quickly see which directories have grown or shrunk. You can see disk space usage trends. You can even be alerted when directories grow (or free space shrinks). In addition, WatchDISK tracks file sizes by extension (so you can very quickly find out how much space .MP3 files are taking on your server volumes).
WatchDISK has been used by administrators for over 11 years.
Short Feature List:
Save data to the included Access database, or to your own MySQL or a Microsoft SQL Server installation (including the freely available MSDE edition)
Shows current directory sizes and past directory sizes allowing you to view usage trends
Automated alerts that warn you when disk space disappears
Single click graphical reports created in Microsoft Excel
Command line support
Data summaries of space used by file type
Liberal licensing allows administrators to monitor as many directories/servers/users as needed