skip to main content
Department of Computer Science University of Colorado Boulder
cu: home | engineering | mycuinfo | about | cu a-z | search cu | contact cu cs: about | calendar | directory | catalog | schedules | mobile | contact cs
home · undergraduate program · senior project · projects · 

Senior Project - DDSR


Deleted Data Space Release

Senior Project: 1998-1999
Peter Alber, Michael Burchett, Kyle Knight, Jay Miller and Scott Saad

StorageTek provides information storage solutions in the areas of high-performance tape drives, automated tape libraries, disk subsystems, networking products, integrated software and consulting. They have developed a prototype storage device capable of storing up to four terabytes of data on a single unit. This device is able to connect to a workstation under a number of different operating systems, including Microsoft Windows NT 5.0 and a variety of flavors of UNIX. The storage device consists of an array of disk drives integrated into a single unit, along with a controller. The controller, responsible for managing read/write operations and other tasks associated with a typical hard drive, is also responsible for allowing the user to view multiple drives in the array as a single drive.

The goal of the project was to provide for what is called deleted data space release (DDSR), a function which assists a disk array subsystem in managing its free space. Since most operating systems, including Windows NT, manage free disk space internally, they do not usually notify a disk subsystem when space has been freed. They only need to manipulate the disk when data is actually being written. However, due to the nature of the disk array, it is necessary that the disk subsystem know both when space is allocated and when it is deallocated on the device. This project, implemented in C as a Windows NT "filter driver," provides this mechanism.

See also:
Department of Computer Science
College of Engineering and Applied Science
University of Colorado Boulder
Boulder, CO 80309-0430 USA
Send email to

Engineering Center Office Tower
ECOT 717
FAX +1-303-492-2844
XHTML 1.0/CSS2 ©2012 Regents of the University of Colorado
Privacy · Legal · Trademarks
May 5, 2012 (14:07)