[Beowulf] quick note on Redhat NFS issues with NAS units

[Sean Dilda]

Joe Landman wrote:

> Folks:
>
>  Been looking into why a Redhat EL3 WS x86_64 client hangs when 
> accessing a NAS based upon SuSE 9x.  Turns out there are two 
> problems.  I can reliably cause the problem to appear/dissappear on my 
> test hardware, and I thought others on this group would like to see 
> what I did to make the problems dissappear.
>
>  Problem manifests itself with RedHat EL3 WS x86_64 clients.  I have 
> not been able to replicate it with non-RHEL3 based clients, on the 
> same hardware, including FC2/FC3/Ubuntu/SuSE9x/... Problem does not 
> show up in 32 bit mode from what I can tell (need more testing but 
> preliminary data seems to support this).  Motherboard are Tyan s288x 
> units.  All have the Broadcom chipset ethernets.
>  By default RedHat installs tg3 kernel modules to drive these chips.  
> I have not been able to make the problem go away using the tg3 
> driver.  So I replaced the tg3 driver with the bcm570x driver from 
> Broadcom's download site.  This did not make the problem go away, 
> though NFS mount now respected the intr option (did not with the tg3).
>  Next, I changed from udp to tcp.  The original fstab line was
>
> 192.168.2.17:/big       /big                    nfs     udp,intr,bg 0 0
>
> and the new one is
>
> 192.168.2.17:/big       /big                    nfs     
> tcp,intr,bg,wsize=32768,rsize=32768 0 0
>
> MTU changes did not affect the results (though they did improve on 
> some of the test timing).

I'm successfully using RHEL3 x86_64 NFS clients mounting from a RHEL3 
x86 server.  My only options are 'rsize=8192,wsize=8192', and jumbo 
frames are enabled.