[OpenAFS] Evaluating AFS for in house use, RFCs...

Mitch Collinsworth mitch@ccmr.cornell.edu
Fri, 3 Feb 2006 11:50:55 -0500 (EST)

On Fri, 3 Feb 2006, Jeffrey Altman wrote:

> I don't have hard numbers.  Its a simple reality.  If you are using an
> AFS cache manager with anything close to a decent cache size, if you
> need to access a file more than once, then the second time you access
> it assuming it has not changed the reads will occur a local disk speed
> instead of WAN speed.

That's a lot of if's.  If you're generating reams of data today and
are only going to come back and analyze it tomorrow or next week then
the cache is not necessarily any help.  If you're generating many GB
of data then the cache still thrashes.  Remember the old UMich paper?

>> The vast majority of users don't care about any of these operations.
>> They just want to save data and retrieve it.  Or maybe it's save it
>> and forget about it.  While installing the client might be a good
>> thing, the user isn't going to buy it based on this logic.  If we had
>> numbers to show how much faster it is, that they would buy.
> Then might I suggest you start running some performance tests.

That's probably a good idea.  My point is that the last time I saw
numbers on this, AFS/RX did NOT handily beat Samba/SMB.  It was in
fact the other way around.  Discovering that this has changed would
be very helpful in convincing people to give AFS a try.