CS262B Reading Summary

Serverless Network File Systems

Thomas E. Anderson, Michael D. Dahlin et al.

Feng Zhou
2/1/2004

Strong points of the paper are:

  1. Just as NOW, the emergence of fast switching LANs is an important propelling reasons to use a de-centralized network file system.  One strong point of xFS is that it can exploit the storage and processing power of multiple workstations/servers while at the same time provides a single view of a file system.  Unlike Andrew or other previous network file systems, xFS not only makes the file system accessible from a network, but also makes the file server a network of machines itself.
  2. Using existing techniques like LFS and Zebra makes xFS easier to construct.  LFS is very useful for each node because it increases write performance and eases local recovery.  Techniques in Zebra, such as the delta log, eases global recovery.
One major flaw.

One of the original usage scenarioes of xFS, i.e. using it between trusted (departmental/company-wide) workstations, is flawed.  This implies heavy management burden.  As computing becomes cheaper and cheaper, the reduction of management overhead becomes more and more important.  Thus xFS in this scenario is a move in the wrong directions.  However, using xFS on a small number of well-management servers, i.e. the other usage scenario, is much better.  Actually I can expect vendors wrapping up a cluster of servers running xFS and sell it as a large scalable storage server.