On Thu, 23 Sep 2004, Richard Kettlewell wrote:
I tried renice 20 [PID of the ftp client], which reported that it had changed the priority of the ftp client from 0 to 19, but this doesn't seem to have speeded up my X applications any, so I'm guessing that nice priority settings only apply to CPU, not to network bandwidth: is this right? If so, how can I make the ftp client be "nice" about network usage?
That is indeed right. You want to use traffic shaping.
Thanks: the documentation pointers allowed me to work out that I need something along the lines of
tc qdisc add dev ppp0 root sfq
which, if I've understood correctly, is strictly"scheduling" rather than "shaping." Unfortunately, this returns the error message
RTNETLINK answers: Invalid argument
and doesn't seem to do anything. A quick google reveals that many people have the same error message, but I'm not sure about the relevance of any of their scenarios.
I fear that the following, from the tc-sfq manpage, might have something to do with it:
Most often, cable modems and DSL devices do not fall into this category. The same holds for when connected to a switch and trying to send data to a congested segment also connected to the switch.
In this case, the effective queue does not reside within Linux and is therefore not available for scheduling,
for verily am I using an ADSL modem. Any more ideas, please?