Slow network with F13

[Bill Davidsen]

john wendel wrote:
> I've got a couple of boxes connected with wire and a gigabit ethernet 
> switch. With F11 on the sending and receiving sides, I see a transfer 
> speed of ~ 40 MB/s transfering large files.  With F13 on the sending box 
> (same box, just new software), I get a transfer speed of ~ 23 MB/s with 
> the same files. The disk read speed on the F13 box looks to be ~ 75 
> MB/s, so it doesn't seem to be the bottleneck.
> 
> I'm not sure where to start looking. Any help will be much appreciated.
> 
Since you only changed the OS at the sending end, that lets out a slowing of 
disk write on the receiver. Since you have tested the speed of disk reads and 
found it adequate, it's likely that the issue is the network code on the sending 
end.

However... do check the speed of reading that particular file. Remember that 
different parts of the disk are faster than others, even on Linux files 
fragment, etc. The easy way to do this is:
   dd if=my.file of=/dev/null
and dd will report the speed. You can see as much as 50% slower on inner tracts, 
so it's at least a possibility.

-- 
Bill Davidsen <davidsen at tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot