There seems to be a lot of confusion surrounding
this topic. The concept in question is descibed in
the following paper:
Heidemann93b
John S. Heidemann and Gerald J. Popek. File System
Development with Stackable Layers. Technical Report
CSD-930019, University of California, Los Angeles,
January, 1993. To appear, ACM Transactions on Computer
Systems, February 1994..
It is available from
http://www.isi.edu/~johnh/PAPERS/Heidemann93b.ps.gz
--
Regards
Joerg
GMD-IPSI, Dolivostr. 15, Zimmer 120, D-64293 Darmstadt
+49-6151-869-786 (Phone), -818 (FAX)