Encyclopedia of Database Systems

2018 Edition
| Editors: Ling Liu, M. Tamer Özsu

Network Attached Secure Device

  • Kazuo GodaEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-1-4614-8265-9_1466


NASD; Object-based storage device; OSD


A Network Attached Secure Device (often abbreviated to NASD) is a networked storage device which offers object-level storage accesses. NASD was first explored in a research project of the same name, which started at Carnegie Mellon University in 1995. NASD is now more often called Object based Storage Device (shortened to OSD).

Key Points

NASD is an approach of decoupling only low-level functions of file systems from NAS devices. A NASD manages only stored objects, each of which is identified with a unique file descriptor, and their additional information such as metadata and attributes, whereas a central policy server manages higher-level information which is used for name space management and authorization. A bunch of NASDs, with the assistance of the central policy server, can together work as a file store. This may look similar to NAS at a glance, but the difference is that most commands and data are directly transferred...

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Recommended Reading

  1. 1.
    ANSI. Information Technology – SCSI Object-Based Storage Device Commands (OSD). Standard ANSI/INCITS 400-2004. 2004.Google Scholar
  2. 2.
    Gibson GA, Van Meter R. Network attached storage architecture. Commun ACM. 2000;43(11):37–45.CrossRefGoogle Scholar
  3. 3.
    Gibson GA, Nagle DF, Amiri K, Chang FW, Feinberg EM, Gobioff H, Lee C, Ozceri B, Riedel E, Rochberg D, Zelenka J. File server scaling with network-attached secure disks. In: Proceedings of the 1997 ACM SIGMETRICS International Conference on Measurement and Modeling of Computer Systems; 1997. p. 272–84.Google Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.The University of TokyoTokyoJapan

Section editors and affiliations

  • Masaru Kitsuregawa
    • 1
  1. 1.Inst. of Industrial ScienceUniv. of TokyoTokyoJapan