Re: Linux shaping packet loss

[gordon b slater <gordslater () ieee org>]

On Wed, 2009-12-09 at 08:02 +0200, Bazy wrote:

> Hi Chris,
>
> Try setting txqueuelen to 1000 on the interfaces and see if you still
> get a lot of packet loss.

Yes, good point and well worth a try. Rereading Chris's post about
"250Mbps" and "forty queues", the "egress" could well be bumping the end
of a default fifo line.

If 1000 is too high for your kit try pushing it upwards gradually from
the default of 100 (?) but back off if you get drops or strangeness in
ifconfig output on the egress i/f.

I append grep-ped ifconfig outputs into a file every hour on a cron job
until I'm happy that strangeness doesn't happen, they never do when
you're watching sadly. 

TC problems aren't always about the TC itself, the physical interfaces
are inherently part of the "system", as my long rambling 5am+
up-all-night-over-ssh post about reseating NICs was trying to hint at.  

Nice one Bazy

Gord