[OpenAFS] FW: TR-62286 Outlook PST files in AFS space

Derek Atkins warlord@MIT.EDU
20 May 2001 09:20:43 -0400

aeneous@speakeasy.org writes:

> > Second, you would need to change the AFS protocol to support byte
> > locks, because you need to get the server to support them.
> Why? The NFS server didn't need to be changed. The locking protocol
> is just a bag on the side.

By definition this is a change in the protocol.  Even though it's "a
bag on the side," it's still a change in the protocol.

> Naturally, new functionality cannot be supported by old 
> clients or servers.  This is a problem?  Calling it incompatible
> is hyperbole.

Not necessarily.  Many features are client-only or server-only
features.  Disconnected operations, for example, is a client-only
feature.  It requires no changes to the server (or the client-server
interfaces) to implement it.  Similarly, better logging is a
server-only feature, again requiring no changes to the client-server
interface (e.g. the AFS Protocol).

The problem is that the _current_ mandate from the OpenAFS Elders is
that we must remain protocol-compatible with IBM/Transarc AFS.  Now,
it may be possible to implement byte-locks and remain compatible.  Or,
it may not.  With NFS's Lockd, what happens if your client is running
version 2 and your server is running version 1?  Does it still work?
Basically, unless you can come up with a protocol-compatible way to do
byte-locking then I highly doubt the code would be incorporated into
the mainline.


       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord@MIT.EDU                        PGP key available