On Fri, 5 Feb 2010 10:39:03 +0100 Claudio Jeker <[email protected]> wrote:
> On Fri, Feb 05, 2010 at 08:59:44AM +0100, Sebastiano Pomata wrote: > > On Fri, 5 Feb 2010 02:05:49 +0000 (UTC) > > Stuart Henderson <[email protected]> wrote: > > > > > On 2010-02-04, Sebastiano Pomata <[email protected]> > > > wrote: > > > > As doublechecking, I tried with another fast server inside the > > > > wan network of our academy, and I'm getting almost the same > > > > results (while absolute speeds are different from before, the > > > > gap is almost the same in magnitude). > > > > > > > > I've read the page about tcptune, it's pretty clear now (values > > > > are almost the same I edited), still not having clear why on > > > > default OpenBSD the transfer rates are so low. > > > > > > we try to have safe defaults for the varioous machines/arch that > > > can run OpenBSD. > > > > > > we would need some kind of auto-tuning to incrrease the defaults, > > > and don't have that yet. > > > > > > > I really can understand this, for the sake of system portability > > and so on. Anyway, I really hardly understand why, without touching > > any of the default settings, download rate from every server would > > never overcome the value of 400 kB/s. Is it all due to the tcp > > windows size? > > > > # sysctl net.inet.tcp | grep space > net.inet.tcp.recvspace=16384 > net.inet.tcp.sendspace=16384 > # ftp ftp://mirror.switch.ch/pub/OpenBSD/snapshots/i386/install47.iso > ... > Retrieving pub/OpenBSD/snapshots/i386/install47.iso > local: install47.iso remote: install47.iso > 150 Opening BINARY mode data connection for install47.iso (255594496 > bytes). > 100% |**************************************************| 243 MB > 00:33 > 226 File send OK. > 255594496 bytes received in 33.38 seconds (7.30 MB/s) > 221 Goodbye. > > Yep, only 400kB/s, no wait... The use of every should be considered > carefully. Yes, our default window size limits download speed. It is > known and there is work ongoing to resolve this in a better way then > just bumping the limit. > There's no polemical intent in my messages, I'm just trying to debug a situation where I'm totally clueless on what's going on. Claudio, I tried your tcp.{send,recv}space settings (default I think) and then downloaded your very same file, stopping at about 400 kB/s. Then increased the same parameters both to 262144 and download speed bumped at over 2.5 MB/s. I can understand that bumping the window size could not be the only solution, in fact I still get ridiculous upload speeds from the OpenBSD box. Did you make any other tuning to the default install to get that high download speed? Thank you
