On Sun, Oct 11, 2009 at 08:57:06AM +0200, Janne Johansson wrote:
> Jose Fragoso wrote:
> > I am running openbsd 4.2 on a box and I would like
> > help trying to identify networking bottlenecks.
> >
> > While trying to download a file from another obsd
> > box at the network using wget, I get very low rate.
> > 100%[====================================>] 61,758,702 2.30M/s
> > 18:03:55 (2.32 MB/s) - `bsd1.1' saved [61758702/61758702]
>
> This one above probably uses the default values you posted below:
> > net.inet.tcp.recvspace=16384
> > net.inet.tcp.sendspace=16384
>
> but..
>
> > But when I use iperf, I get quite high transfer rates:
> > TCP window size: 256 KByte
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> ..this one sets a higher value for itself.
>
> > My question is what could be causing the tcp poor performance?
>
> Try setting send/recv-space to 256k and re-test with wget in order to
> actually make the two tests use the same limits. Since the wget test was
> both to/from "another obsd", make sure you change both sides and restart
> the data serving application at the other end so it picks up the new
> space (dont know if it is read per connection or per binding of a
> socket, so a safe bet is to restart the app, I guess)
Philip's advice to eliminate the disk variable from the equation is
much better and should be tried first.
-Otto
