NEC Laboratories America
4 Independence Way
Suite 200
Princeton, NJ 08540

(609) 951-2672

Bio

I am a Research Staff Member in the Storage Systems Department.  My interests include file systems, storage systems, operating systems, and networking.  Before coming to NEC Laboratories, I worked at EMC/Crosstor on disk-based file systems, stackable file systems, and storage-area networks.  Before that, I worked at AT&T Bell Laboratories in the UNIX System V kernel development group.


Work

• HYDRAstor File System -- a file system built on top of a content-addressable storage system.  Link to FAST'10.
  
• NFS Performance Enhancements -- NFS client changes to improve the throughput of large sequential write workloads. Test results from an early version can be found here.  Source code from the final version can be found here.
  

Publications

• S. Rago, A. Bohra, and C. Ungureanu.  "Using Eager Strategies to Improve NFS I/O Performance," 6th IEEE International Conference on Networking, Architecture, and Storage, July 2011. (Awarded best paper.)
  
• C. Ungureanu, A. Aranya, S. Gokhale, S. Rago, B. Atkin, A. Bohra, C. Dubnicki, and G. Calkowski.  "HydraFS: A High-Throughput File System for the HYDRAstor Content-Addressable Storage System," Proceedings of the 8th USENIX Conference on File and Storage Technologies, February 2010.
  
• S. Yin, Y. Luo, L. Zong, S. Rago, J. Yu, N. Ansari, and T. Wang.  "Storage Area Network Extension over Passive Optical Networks (S-PONs)," IEEE Communications Magazine, January 2008.
  
• R. Stevens and S. Rago.  Advanced Programming in the UNIX Environment, 2nd Edition.  Addison-Wesley, 2005.  Book's web site.
• M. Clark and S. Rago.  "The DeskTop File System," Proceedings of the Summer 1994 USENIX Conference, pp. 113-124.
  
• S. Rago.  UNIX System V Network Programming.  Addison-Wesley, 1993.
• S. Rago.  "A Look at the Ninth Edition Network File System," UNIX Research System Papers, Tenth Edition, Volume II, 1990, pp. 513-522.
  
• S. Rago.  "Out-of-Band Communication in STREAMS," Proceedings of the Summer 1989 USENIX Conference, pp. 29-37.
  

Patents

• "Apparatus and Method for Maintaining a File System Index," U.S. Patent No. 8,135,763.
  
• "Selection of Migration Methods Including Partial Read Restore in Distributed Storage Management," U.S. Patent No. 8,055,724.
• "File System Query and Method of Use," U.S. Patent No. 7,805,416.
  
• "Apparatus and Method for Building a File System Index," U.S. Patent No. 7,783,615.
  
• "Self-describing File System," U.S. Patent No. 7,167,867.
  
• "Distributed Resource Management in a Storage Area Network," U.S. Patent No. 6,826,580.