UCLA File System Stacking FAQ

Q: What is stackable filing?

See an on-line description of stacking or [Heidemann94a].

Q: What are good references for UCLA stackable filing?

The oldest reference is [Guy90b] where we describe Ficus as constructed from stacking. The best reference is probably [Heidemann94a].

Q: What are other references for stackable filing?

Important related work about stackable filing has been done at Sun Microsystems. David Rosenthal [Rosenthal90] and then Glenn Skinner [Skinner93] represent one line of development. The Spring project (at SunLabs) developed a different approach to file system stacking [Khalidi93b]. (These references are not yet on-line. As an interim solution send e-mail for complete references.)

Q: How do I get UCLA stackable filing source code?

The UCLA file system stacking implementation is freely available. Unfortunately, because stacking requires modifications to the surrounding operating system, there are two different distributions available. The SunOS distribution includes all stacking services but requires a SunOS 4.x source license. The BSD distribution includes a subset of services but is freely distributable.

To obtain the SunOS release, please contact johnh@isi.edu. This release will consist of a stable snapshot of our development environment.

The freely distribution portions of the stackable filing framework and the SunOS-based null layer are now available on the web.

The BSD release includes only in-kernel stacking services. It does not support transport layers and user-level layer development. There are two 4.4BSD releases, 4.4BSD and 4.4BSD-lite. For information on obtaining BSD, contact:

       Pauline Schwartz, Distribution Coordinator
       Computer Systems Research Group
       Computer Science Division, EECS
       University of California
       Berkeley, California 94720
       

A more practical source for complete, current versions of 4.4BSD-systems are the NetBSD project, the FreeBSD project, BSDI, and the OpenBSD project,

Q: What is the relationship between UCLA stackable filing and Ficus?

Ficus is really two things, the Ficus project and the Ficus replicated file system. The Ficus project is the name for a collection of research and researchers at UCLA under the direction of Dr. Gerald Popek. The Ficus replicated file system is a file system built with UCLA stackable layers.