Re: NIC on morollan
Hi,
I installed the beacon on my workstation
(dcpiper.informatics.indiana.edu) and have not noticed any difference
running for a number of hours yesterday (with checksum offloading
disabled) and today (with checksum offloading enabled-default). I get no
loss whatsoever. I will talk about this with our network people since
the two machines are within the same room, though not necessarily the
same switch. I'll find out more and let you know of any 'revelations' :)
Derek
PS: The beacon page has an awful lot of 'NA's all over it. Someone kill
the US-Australia link?
David Gwynne wrote:
> From: "Mitch Kutzko" <mitch@ncsa.uiuc.edu>
>
>>At 01:52 AM 10/27/2004 +1000, Christoph Willing wrote:
>>
>>>Mitch,
>>>
>>>I see that you're the contact for morollan.ncsa.uiuc.edu - can you
>>>confirm/deny whether its NIC uses the Intel e1000 chip? Its output in
>>>the central_loss page shows a pattern of losses which we think can be
>>>attributed to this driver/chipset.
>>>
>>>chris
>>
>>Hi, Chris -- Sorry to provide you with a "bad" data point for your theory,
>>but here's the info for the NIC on morollan:
>
>
> Perhaps this isn't a bad data point after all. Both the intel gigabit and
> the 3com 3c905 tornado chipsets have support for tcp/udp checksum
> offloading. In theory though, this should help improve responsiveness since
> the host computer has to do less work processing the packets. I believe the
> linux drivers support this offloading for both controllers. I know it is on
> by default in the e1000 driver.
>
> I have tried disabling the checksum offloading with the e1000 driver which
> really did improve the pattern of loss visible on the central_loss page, but
> didn't eliminate it entirely. I would have liked to have attributed the loss
> to network conditions, but other hosts on the same subnet using a broadcom
> gigabit chipset experienced no loss.
>
> David Gwynne
>
>
>>[root@morollan root]# cat /etc/sysconfig/hwconf
>>[....]
>>class: NETWORK
>>bus: PCI
>>detached: 0
>>device: eth0
>>driver: 3c59x
>>desc: "3Com Corporation|3c905C-TX/TX-M [Tornado]"
>>network.hwaddr: 00:04:75:AB:2A:5C
>>vendorId: 10b7
>>deviceId: 9200
>>subVendorId: 10b7
>>subDeviceId: 1000
>>pciType: 1
>>pcidom: 0
>>pcibus: 2
>>pcidev: c
>>pcifn: 0
>>[....]
>>
>
>
>
>
--
Derek Piper - dcpiper@indiana.edu - (812) 856 0111
IRI 323, School of Informatics
Indiana University, Bloomington, Indiana