How to enable JUMBO frames on a tiny subnet for NFS to work

Hi,

I was able to build a NFS server and a NFS client using OpenSuse 11.3 and connect them together using gigabit ethernet through a switch. These are the only 2 devices on this net (192.168.1.xx). I tried to set the MTU to 9000 and 9014 but learned that the Realtek 8169/8111 only support up to about 7200 MTU. So I inserted Intel NIC cards on both and set both to 9000. The system accepts this and I can ssh from one machine to the other. Both NFS client and server start w/o issue and the client mounts the device just fine. But when I try to copy a file on the NFS client from the local disk to the server, the client just hangs and I have to physically turn the machine off in order to get it to work. Both systems are using the stock software from the DVD (I didn’t update either).

What’s wrong? Please help; thank you.

Best,
Chris

zchrish wrote:

>
> Hi,
>
> I was able to build a NFS server and a NFS client using OpenSuse
> 11.3 and connect them together using gigabit ethernet through a
> switch. These are the only 2 devices on this net (192.168.1.xx). I
> tried to set the MTU to 9000 and 9014 but learned that the Realtek
> 8169/8111 only support up to about 7200 MTU. So I inserted Intel NIC
> cards on both and set both to 9000. The system accepts this and I can
> ssh from one machine to the other. Both NFS client and server start
> w/o issue and the client mounts the device just fine. But when I try
> to copy a file on the NFS client from the local disk to the server,
> the client just hangs and I have to physically turn the machine off in
> order to get it to work. Both systems are using the stock software
> from the DVD (I didn’t update either).
>
> What’s wrong? Please help; thank you.

Does your switch work with jumbo frames?


Per Jessen, Zürich (9.0°C)
http://en.opensuse.org/User:pjessen

I have tried 2 different scenarios with 2 different sets of computers.

First set: realtek NICs with 7200 MTU with a Netgear 16 port GS116 switch
2nd set : Intel NICs with 9000 MTU and a Frys 5 port switch

I read on Netgear www that jumbo frame support is available only on certain serial numbers of the GS116 so I need to investigate whether this is the source of error on set (1).

I cannot determine whether set (2) has jumbo frame support but since the switch costs $23.00 USD, maybe is doesn’t support it.

I will find a switch that does support jumbo frames and re-test.

Thanks,
Chris

zchrish wrote:

>
> I have tried 2 different scenarios with 2 different sets of computers…
>
> First set: realtek NICs with 7200 MTU with a Netgear 16 port GS116
> switch
> 2nd set : Intel NICs with 9000 MTU and a Frys 5 port switch
>
> I read on Netgear www that jumbo frame support is available only on
> certain serial numbers of the GS116 so I need to investigate whether
> this is the source of error on set (1).
>
> I cannot determine whether set (2) has jumbo frame support but since
> the switch costs $23.00 USD, maybe is doesn’t support it.
>
> I will find a switch that does support jumbo frames and re-test.

In my (albeit limited) experience, you’ll need a near-professional level
switch to get it. LIke you’ve seen, some of the Netgear boxes will do
it, but not all. I’ve tried out the realtek NICs myself with the 7000
baby-jumbos, only to fall flat on my face when the switch
said “boohoo”.


Per Jessen, Zürich (9.9°C)
http://en.opensuse.org/User:pjessen

Just a thought,
Depending on distance and eventual Production configuration, would it make sense to bypass the switch and create a dedicated line?

Tony