Darrell Don Earl Long is an American computer scientist and computer engineer who is the inaugural holder of the Kumar Malavalli Endowed Chair of Storage Systems Research and Distinguished Professor Emeritus of Engineering at the University of California, Santa Cruz.

[8] Long has held visiting faculty positions at the Université Paris–Dauphine (Paris IX), the Conservatoire National des Arts et Métiers, the Université Paris–Descartes (Paris V), Sorbonne Université (Pierre et Marie Curie, Paris VI), the University of Technology, Sydney, the Center for Communications Research, the United States Naval Postgraduate School and is Professor ad Honorem de la Universidad Católica del Uruguay.

[6] In 1991,[14] Long worked on the idea of storing metadata separately from data in the Swift file system.

The Ceph[16] distributed file system was first designed and implemented in the Storage Systems Research Center in 2006[17] by Sage Weil and other members of the SSRC under the direction of Long, Professor Ethan Miller, Professor Scott Brandt, and Dr. Carlos Maltzahn.

[22] Beyond these areas, Long has written research papers on web caching,[23] power-aware hard disk management in mobile computing,[24] and low-bandwidth multicast techniques for video on demand,[25] among other topics.