Re: RFC: NFS trunking (multiple TCP connections for a mount

From: Gerrit Kuehn <gerrit.kuehn_at_aei.mpg.de>
Date: Tue, 29 Jun 2021 06:06:11 UTC
On Tue, 29 Jun 2021 00:23:21 +0000
Rick Macklem <rmacklem@uoguelph.ca> wrote:

> I don't understand how multiple TCP connections to the same
> server IP address will distribute the load across multiple network
> interfaces?
> I thought that lagg would have handled this?

I don't think this targets multiple interface situations. In my
experience it is next to impossible to max. out a 10G connection with a
single NFS connection running over it. The NICs have several
independent queues like so (systat -ifstat):

ixl0:aq
ixl0:rxq0
ixl0:rxq1
ixl0:rxq2
ixl0:rxq3
ixl0:rxq4
ixl0:rxq5
ixl0:rxq6
ixl0:rxq7

A single connection will only use one of these, limiting the overall
throughput. Spreading load across multiple connections sounds quite
useful to me in this situation.


cu
  Gerrit