[OpenAFS] AFS over high(ish) latency link

Tracy Di Marco White afs-info@gendalia.org
Wed, 18 May 2005 11:08:45 -0500

In message <428AC45A.9060105@andrew.cmu.edu>, Peter Nelson writes:
>Hi, I'm wondering if anyone has experience using AFS over higher latency 
>links, where by higher I mean residential broadband.  I am only able to 
>achieve rates of about 150k/sec across my cable connection using AFS 
>while I can download at about 500k/sec using http from the same server.  
>I believe the culprit is the fact that my ping times are almost 100ms 
>and somewhere the rx window size is limiting the amount of in-flight 
>data.  Does anyone have suggestions as to what to tune, including 
>#DEFINE's in the source?

I access my afs cell at work over my broadband link while at home regularly,
and I access my afs cell at home from work, pretty much just as regularly.
The only problems I've really noticed are NAT related, rather than broadband
related.  And even to that, things work through my NAT, it's just reads are
slow, while writes seem to happen at wire/disk speeds.  (Slow meaning
I can play mp3s through my NAT out of AFS, but not videos.  Particularly
bad were the Star Wars trailers at high resolutions.)  I'm not sure, but I
think most people have more problems than I do with NATs & AFS (in part
because arla doesn't have the slow read problem through a NAT, and most
of my machines are NetBSD, and so the AFS client I use most must be Arla).
Experiments with OpenAFS for Windows & Mac OS X show the problem with
very slow reads on both.