1. Naming in Distributed File Systems Tao Zhang Advanced Operating System Professor: Dr. Yanqing Zhang

2. Guideline Naming in NFS File Handles Automounting Global Name Space Service

3. Naming in NFS NFS naming model is to provide clients complete transparent access to a remote file system

4. Naming in NFS Allow client to mount a remote file system into its own local File system. Only Allow client to mount part of a file system instead of an entire system.

5. Drawback of Naming in NFS Users do not share name space. Client A: /work/me/mbox Client B: /remote/vu/mbox

6. Solution to Naming in NFS Provide a partly standardized name space for each client.

7. Solution to Naming in NFS NFS server can itself mount directories that are exported by other servers. NFS does not allow to export directories to its own clients.

8. Solution to Naming in NFS If name resolution is iterative, then to resolve the name /bin/draw/install: Client will contact server A once it resolved /bin and requests A to return a file handle for directory /draw. Server A return a file handle that includes an identifier for server B, only B can resolve the rest of the path name, in this case /install

9. File Handles A file handle is a reference to a file within a file system. It is created when the file is created. A file handle is implemented as a true identifier for a file relative to a file system. A server does not reuse the file handle after deleting the file.

10. Automounting How to decide when a remote file system should be mounted? Example: client A logs into its workstation, has access to client B’s public files. Client B’s directory should also be mounted? On-demand mounting of remote file system is handled in NFS by an automounter.

11. Automounting

12. Global Name Space Service (GNS, 2004) Integrate existing file systems into a single global name space but using only user level solutions. GNS does not provide interface to access files. GNS has the advantage of decoupling the naming files from their actual location.

13. Future work Content-Centric Network (CCN) is promising as a future Internet architecture. The aim of Content-Centric Network is trying to distribute digital contents among the content provider and consumer. Naming those content is still a challenge work to make sure contents are identified by unique name.

14. References Andrew S. Tanenbaum, and Maarten Van Steen. Distributed Systems Principles and paradigms. Second Edition, 2007 Safdar Hussain Bouk, Syed Hassan Ahmed, Dongkyun Kim, “Hierarchical and hash based naming with Compact Trie name management scheme for Vehicular Content Centric Networks,” Computer Communications, Nov 2014