Extended file system on UNIX 4.2/4.3 BSD

[Doug Kingston]

The answer is that there is ongoing work on a remote file system
for 4.3BSD.  I am currently about to Alpha test a remote filesystem
whose development started at BRL with help from Dan Tso at Rockafeller
University, and has been continued here at CWI (mcvax).   The system
uses a kernel mode client and a user mode server.

The RFS is completely transparent to the client system.  No user mode
changes are required except to replace the mount/umount programs and
recompile the kmem readers (due to changes in some data structures).
It supports remote chdir, remote core dumps, and all other 4.{2,3}
filesystem related system calls.  Remote file systems are currently
mounted just as regular filesystems are mounted.  This mechanism may
be augmented to happen automatically later.  Authentication is currently
done via the hosts.equiv/.rhost mechanism.  Other security measures can
be easily implemented in the user mode server.

Current performance 750/file to 750/dev/null is about 30 Kbytes per second.
This should improve but will never exceed that of RCP and should be slightly
less due to the added overhead of true RPC over the TCP connection.

Now the good news:  The CWI/BRL RFS will be made available on mod.sources
when it has sufficently stable.  I expect this to be just after
4.3BSD is released, but not before the end of January.  I will be sending
diffs of the altered files and the new files I wrote.  The RPC protocol has
been designed to map very closely to the 4.2BSD system calls and has
provisions for negotiating byte order, directory format and other machine
and OS dependent actions.  It currently uses TCP but is quite able to
exist on other reliable transport systems, either STREAM or DGRAM.
RDP would be a prime choice.

It should port easily to 4.2BSD and 4.2BSD derived systems.

When the system is about to be come available, a note will be sent to
this newsgroup (amongst others).  If you have specific inquiries about
this, please address them to me personally:  dpk at mcvax.uucp.

Cheers and Merry Christmas!
	-Doug-