Extended file system on UNIX 4.2/4.3 BSD

[Todd Brunhoff]

I have posted to mod.sources complete software and documentation for
installation, maintenance and adjustment of RFS, a public domain,
kernel-resident distributed file system, written at Tektronix Computer
Research Laboratories* by myself for partial fulfillment of the
master's degree program at the University of Denver.  It was designed
to provide complete transparency with respect to file access and
protections for all programs whether they use local or remote files and
directories.  It has been installed on VAX BSD 4.2 and 4.3 UNIX,
Pyramid 4.2/5.0 UNIX, version 2.5, and on a Tektronix internal
proprietary workstation, called Magnolia.  The instructions are
designed in a way that keeps all changes separate from your standard
sources, in hope that it will encourage sites to try the installation.

The version posted is release 2.0+ (plus bug fixes, easier installation
with patch, etc.), for those of you that may have heard of it.  I
mention this also because I am told that plain old 2.0 will appear on
the BSD 4.3 tape under contributed software from U of Colorado at
Boulder.

Before you ask, it is "stateful".  It is completely implemented except
for ioctl() and select().  This includes the file locking facility,
flock(2), which has been discussed here recently.  The raw speed of
performing a read(2) or write(2) type of system call remotely is about
25% - 40% that of local speed.  Typically, this tends to make programs
run about 50% - 90% of normal speed, because most programs spend a
majority of their time doing computing, or local I/O (like display to a
terminal).  This makes it roughly twice as fast as rcp.  The bulk of
the use it sees here in teklabs, is among 50 or so Magnolias, an 11/780
and an 11/750.  Its applications here are largely
	- distributed program development
	- distributed libraries for local program development
	- news
	- Rand MH mail
	- distributed font files for troff
	- distributed man pages
And just about any other application that enables us to move large amounts
of data off of the workstations and onto the VAX.  The nicest win is with
distributed program development where you keep all the source for a project
on the vax, and each user (having a Magnolia) uses the source via RFS.

I am happy to answer questions and redistribute bug fixes.  I hope you
find this useful.


			Todd Brunhoff
			toddb%crl at tektronix.csnet
			decvax!tektronix!crl!toddb

* RFS should not be confused with another completely different (but
  excellent) implementation from Tektronix available on the 6000 series
  workstation, called DFS, and done by a separate product group.  The
  work on RFS was designed and written strictly by the author of this
  paper at about the same time as DFS, and draws none of its
  implementation details from DFS.  RFS is public domain, while DFS is
  proprietary.