According to Jan Harkes:
>
>Partial caching just won't work if you want to have any guarantees on
>consistency, just look at the mess AFS3 made of it.
>

Well, there may be a way around having to write back an entire large
file (I may be making some invalid assumptions about the Coda protocol
here though :-)

If the file is in cache and a small part of it is updated then perhaps
rather than writing back the entire file a rsync[1] like protocol
could be used to transfer the file back.  Andrew Tridgell has a
library style version of rsync[2] that can be used to transfer files
between peers.  Would it be possible to bolt rsync into the file
transfer?  I realise that this may break compatibility (maybe, unless
the link style can be "negotiated" at connect time) but the decrease
in traffic due to a cache write back may be worth while.

[1] look at http://www.samba.org/ and follow the rsync link at the
    bottom of the page
[2] Which I cannot find a reference to but Andrew keeps mentioning
    it...

-- 
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Brett Lymn, Computer Systems Administrator, BAE SYSTEMS
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