Re: jumbograms (& em) & nfs a no go

On Thu, 30 Oct 2003, Sam Leffler wrote:

> On Thursday 30 October 2003 04:46 am, Michal Mertl wrote:
> > I wanted to test gigabit network performance and found out that current
> > (from 5.0 to up to date -current) doesn't fully work with jumbograms (MTU
> > set to 6000), Intel adapters and nfs (both UDP and TCP).
> >
> > I checked that the same thing works with 4.9.
> >
> > I then left one computer at 4.9 and upgraded the other to 5.0. When I
> > mount a partition from 5.0 machine I found out, that copying reliably
> > works only from 5.0 to 4.9. The other way around I see messages 'em0:
> > discard oversize frame (ether type 800 flags 3 len 67582 > max 6014)' on
> > 5.0 and the copying stalls. On 4.9 machine I later see 'nfs server
> > 10.0.0.2:/usr: not responding'. The interface is stuck for some time - can
> > be revived by changing mtu back to 1500 and down/up sequence.
>
> I've ran many jumbogram tests of machines connected with a cross-over cable
> and em devices at each end.  If you've got a swtch in the middle make sure it
> does the right thing.

I also used exclusively crossover cable. The same configuration worked
with 4.9. The problem appears only with NFS.

I can repeat the whole test once again to make sure I didn't overlooked
anything. It will take some time because I had to put one of the servers
into production.

-- 
Michal Mertl