NFS over LAGG / lacp poor performance

[Steven Hartland]

----- Original Message ----- 
From: "Gerrit Kühn" <gerrit.kuehn at aei.mpg.de>


> On Fri, 25 Apr 2014 15:25:04 +0100 "Steven Hartland"
> <killing at multiplay.co.uk> wrote about Re: NFS over LAGG / lacp poor
> performance:
>
> SH> We saw the issue with 10-RELEASE last weekend on a machine with 6 x
> SH> igb's where by the system was burning CPU in the interrupt handlers,
> SH> setting num_queues to 2 fixed the issue we where seeing.
>
> Sounds like reducing the queues is the first thing to try then, thanks!
> How did you verify that the irqs were the culprit? Apart from the high irq
> rate in vmstat I do not see any other load values skyrocketing.

It was more CPU usage in top.

Run top then enable system processes (shift+S) and threads (shift+H) then
disable idle process display (z) if your seeing significant CPU usage to
the igb interrupt handlers try reducing the number.

    Regards
    Steve