Along these lines, I have a wish-list feature that would be very powerful
and simple to add to the server.  A simple command to get the checksum or
cryptographic hash of a file on the server would have a number of useful
applications and wouldn't add much complexity to the server.

About the rsynch, this may sound wird, but I actually feel that such a
feature should be added at the transport layer of the protocol and NOT at
the file system level.  So in the case of coda it would probably make
sense to create an rsync/sftp side effect for rpc2.  Of course this would
add quite a bit of overhead to the server as it would have to keep many
different versions of the same file.

> The file write-back to the server could also include an intelligent way
to
> send data, ala rsync (http://samba.anu.edu.au/rsync/) : only
> modified portions of the files are transfered from the client to the
> server. Thus applications that open files for writing , and do not
> modify them, will benefit greatly from that : no file transfer at all
will
> occurs (after checksuming the files).
> This only involves the file transfert, not logging or anything else, and
> the code is already done and greatly working in rsync.