Just for grins, I built the 4.7.4 source under FreeBSD 2.2.6.  The
only hitch was that coda.h didn't end up including <sys/time.h>, and
therefore timespec wasn't defined.  Other than that, it built.
Because of my later lossage, I didn't try to figure out the twisty
maze of ifdefs and determine how to fix this without breaking anything
else.  I then tried the 4.7.4 venus on a system with a 4.6.5
(patch-4.4.?) kernel.  It gave me some message about can't mount /coda
or can't open cfs0.

Before I try any further, is there any reason to expect this to work?
Or do I need the 4.7.4 kernel version?

On another note:
I had another client kernel crash.  It was in cfs_fbsd.c:cvref, and
hit the panic with usecount <=0.   I think this had to do with killing
venus while the network communication was wedged, but I can't
reproduce it at will.  Should I be using 4.7.4 kernel/user code on the
clients?  It seems like it has changed a bit and perhaps debugging the
4.6.5 stuff is not useful.

I tried to run coda across a firewall not administered by me (server
out, client in).  I found that the venus to codasrv messages went out
and the replies came back, but that the codasrv-se to venus-se
messages were blocked.  While I know I need to fix the firewall to
treat these as part of the same 'connection', I found that this wedged
the client particularly badly.  I expected venus to give me 'operation
timed out' after a while, but it seemed not to (simple ls of /coda
which has two dirs project and home - nothing fancy).  tcpdump showed
that the basic rpc request/response were getting through, but not the
-se stuff.  So it might be that this isn't interpreted as failure, but
causes continuous retries.  

I don't know if it is possible to make the client send a udp datagram
from venus-se to codasrv-se when expecting side effect packets; this
would feel kludgy but probably cause coda to work across more
firewalls, as not everyone is fortunate enough to be able to cause
theirs to be changed.  I haven't looked into this.

The good news veiled in this message is that coda is already working
well enough for me that I'm expanding the user community to about 6
from 1.2 people.

        Greg Troxel <gdt_at_ir.bbn.com>