[OpenAFS] cache updates to server

Juan Carlos Schroeder jcsc@adinet.com.uy
Tue, 7 Sep 2004 13:38:20 -0300


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
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

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