On Mon, 3 Dec 2001, Hartmut Reuter wrote: > It' not the server, but the client who starts the update. The client > will send to the server only the dirty chunks, means the chunks which > have been totally or partially rewritten. After the update in the server > the other client in your example who has got a copy of the file will get > a callback-call saying: your data are invalid.
That's correct; only the dirty chunks will be written back to the server. However, writing _any_ chunk back changes the data version of the file, which means that any cached copies of that file on other clients are invalidated in their entirety -- the data version and callback mechanisms operate on a whole-file granularity. This is one of the things that made AMS perform so poorly on bboards with frequent delivery and large readership -- every time a message was delivered to a folder, anyone reading that folder would end up having to fetch a new version of the directory and msgdir. Of course, refetches are done lazily -- a client with an outdated version of a file won't bother to refetch it unless and until it needs the data. -- Jeffrey T. Hutzelman (N3NHS) <[EMAIL PROTECTED]> Sr. Research Systems Programmer School of Computer Science - Research Computing Facility Carnegie Mellon University - Pittsburgh, PA _______________________________________________ OpenAFS-info mailing list [EMAIL PROTECTED] https://lists.openafs.org/mailman/listinfo/openafs-info
