[OpenAFS] UDP slowness remedies?

Eric Chris Garrison ecgarris@iupui.edu
Fri, 22 Oct 2010 13:04:37 -0400

So, I'm doing a mass migration of AFS volumes from one campus to
another.  Both machines have Gigabit interfaces, and we have a 20 Gig
link between the campuses that I understand to be not at all saturated.

However, I'm seeing a transfer rate of only about 30 Mbits/sec
(according to iftop) between the two machines.  I'm working on it with
my local network people, but it seems to be a UDP issue... if I use
iperf with defaults for UDP, I get about 1 Mbit/sec.  If I increase the
buffer size to 1024M, it screams along at 900+ Mbit/sec.

So how's this work with AFS/rx?  Is there something I can tweak to
increase UDP transfer speed?

Any advice would be appreciated.