Re: Jumbo Frames with em

On 9/4/06, Gleb Smirnoff <glebius_at_freebsd.org> wrote:
> On Sun, Sep 03, 2006 at 08:46:21PM -0500, Derrick T. Woolworth wrote:
> D> I'm running -current on a NFS file server with a 3ware controller
> D> striping across multiple disks.  The box uses the em driver with the
> D> mtu set to 8192 - client machines connecting via NFS that are also
> D> running -current with bge drivers with the mtu set to 8192 (and jumbo
> D> frames enabled on the switch)...
> D>
> D> The em driver's README says that UDP and Jumbo Frames don't play well
> D> together - just wondering if this would have any impact on NFS over
> D> TCP?
>
> This comment is quite old. It may happen that this isn't true anymore.
> May be developers from Intel will comment on this.
>
> D> Does anyone know anything about the future of the em driver or
> D> bge driver that might have performance issues with Jumbo Frames?
> D>
> D> I'm only ever seeing the storage system write about 10 to 15MB (bytes)
> D> per second over NFS.
>
> Have you tested the performance with ftp, netcat or some network
> benchmarking tool? The problem may be in NFS not in driver.

Its not entirely clear in your post Derrick, are you using TCP or UDP
NFS?

Jack