Subject: Re: NFS hang problem
To: None <netbsd-help@netbsd.org>
From: Russell McManus <russell_mcmanus@yahoo.com>
List: netbsd-help
Date: 06/09/2003 09:02:53
david@l8s.co.uk (David Laight) writes:
> > Sorry to be following up to myself, but I tried the same test with a
> > PCMCIA ethernet adapter that shows up as ex0 instead of the wireless
> > card, and everything worked OK. So there is something strange going
> > on with the wireless interface.
> >
> > > I've got an NFS server running netbsd-1.6 i386, and a laptop machine
> > > NFS mounting a filesystem from the server.
> > >
> > > The filesystem mount is accessible, however when I try to cat a large
> > > file, the cat command hangs, and in fact is not breakable with ^C.
> > > cat on small files works fine.
>
> How large is large?
The file is 5MB.
> I suspect that something between your server and the client doesn't
> have enough buffer space to hold an entire UDP message. So you are
> getting lost packets and lots of retries. If the error is systematic
> then the retries won't succeed either.
>
> Likely places where packets are lost:
> - the ethernet -> wireless bridge (because it does rate adaption)
> - the wireless card (because you cant read data off it fast enough)
>
> Try changing the mount to use 8k (from 32k) reads and writes.
I will try this and reply with more information. Thanks for the
suggestion.
-russ