On Thu, 20 Feb 2014 14:33:15 +0100 nicolas prochazka <prochazka.nico...@gmail.com> wrote:
> I do some benchmark , > cat /afs/mycell.com/bigfile > /dev/null on openafs clients > and i see a bottleneck of 25MBytes/s on server side ( fileserver process) . > My ethernet link are 1Gbit/s > > How can I suppress this bottleneck ? Do you know what the RTT is between the server? (just 'ping' the server for an approximation) The maximum theoretical throughput you'll get from openafs right now is somewhere around ((32 * 1400) / RTT) bytes per second (due to some limitations in the transport mechanism). That means if your RTT is on the order of 10ms, the maximum throughput you'll see is is 4 or 5 MiB/s. If your RTT is around 1ms, you'll see a maximum of around 40 or 50 MiB/s. That is the theoretical max, so the actual throughput you'll see will be less. There are other potential bottlenecks, of course, but that is often the biggest factor when someone is surprised at the low transfer rates that they see. There are some efforts underway to alleviate those restrictions, but you can't do much about it just by "tuning" clients or servers etc. -- Andrew Deason adea...@sinenomine.net _______________________________________________ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info