Re: NFS and kernel 2.6.x

Andrew Morton
2004-04-16T01:54:20Z

Trond Myklebust <trond.myklebust@fys.uio.no> wrote:
>
> På to , 15/04/2004 klokka 18:14, skreiv Charles Shannon Hendrix:
> >
>
> > NFS server:
> >
> > Sun SS5
> > 10baseT ethernet (100baseT card available, not used)
> > NetBSD 1.6.1
> > pretty much a plain vanilla server setup
> >
> > Network:
> >
> > simple LAN with three machines, connected via a full duplex
> > multi-speed switch
> >
> > NFS client:
> >
> > vanilla PC
> > Intel Pro/100 ethernet
> > Slackware 9.1
> > Linux kernel 2.6.5, plain with no mods or patches, only enough
> > drivers and features enabled to run my workstation
> > configuration as close as I could get to my Linux 2.4
> > kernel
>
> This is pretty much covered in the NFS FAQ entry B10.
>
> You are experiencing the classical effects of using unreliable transport
> (i.e. UDP) on a mixed speed network. Writes to the server are getting
> lost, because it is on a slow segment that cannot keep up with the
> faster 100Mbit clients.

But Charles was seeing good performance with 2.4-based clients. When he
went to 2.6 everything fell apart.

Do we know why this regression occurred?