[OpenAFS] cache updates to server

[Jeffrey Altman]

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The Windows cache and the Unix cache are completely different beasts.
The Windows client does not cache writes and then commit them on file
close.  The Windows client sends the writes to the server immediately.

Microsoft Office applications use Overlapped I/O to perform writes to
the server.   The OpenAFS SMB/CIFS Server does not guarrantee that the
writes are performed in order or that the responses are sent in order
to the Windows SMB/CIFS client.  The Windows client therefore detects
delayed write failures and terminates the operation prematurely.

There is no configuration which can be performed.  I suggest you upgrade
to 1.3.71 because (1) that is the current stable; and (2) it makes some
changes to improve the behavior of OpenAFS with MS Office.

Jeffrey Altman


Juan Carlos Schroeder wrote:

> Hi:
> 
> I wanted to ask some questions about caching in AFS.
> I've used a Windows clients (1.3.66) with a RH8 Linux (1.2.11) server to
> test "write" operations performed by MS Word clients. The connection betwwen
> clients and servers is a very low bandwidth connection (64Kbps).
> Using this applications in the clients, I've found that "write" operations
> are "synchronous" on the server, and each time I save the document, the
> applications hangs waiting the updates to be propagated to servers. That
> makes the usage very annoying each time I perform a "save" operation because
> the AFS protocol seems to be very inefficient (in KB/s transferred in saving
> the document) in these updates, because with a 250KB document the save
> operation lasts up to 2 minutes.
> 
> The questions are:
> 1) I wanted to ask if I wanted to ask if the "consistency" model for writes
> is to update synchronously servers each time a "write" operation is
> performed.
> I've read that AFS updates servers when the file is "closed". Is this true
> or updates are sent also every time the file is saved? May this happen
> because MSWord closes the file each time it is saved?
> I've not used Linux clients, so I wanted to ask if this is the same for
> them.
> 
> 2) In case of being "true" that updates are sent every time the file is
> saved, I wanted to ask if there is any configuration settings for the cache
> or anything to optimize the performance of the protocol for my particular
> needs. These are mostly creation, edition and update of small documents
> (most of them less than 200Kb, and the rest not more than 500 KB, and of
> course the low bandwidth connection).
> 
> Thanks in advance,
> Juan Carlos
> 
> 
> 
> _______________________________________________
> OpenAFS-info mailing list
> OpenAFS-info@openafs.org
> https://lists.openafs.org/mailman/listinfo/openafs-info

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