[Beowulf] tcp error: Need ideas!

Gerry Creager gerry.creager at tamu.edu
Sun Jan 25 12:29:07 PST 2009

Joe Landman wrote:
> Gerry Creager wrote:
>> Joe Landman wrote:
>>> I wonder if the switch could be implicated.  We have seen some 
>>> (cheap) GbE switches not support (in practice) jumbo frames 
>>> (irrespective of literature).
>> Been there, done that.  HP claims to be able to handle packets up to 
>> 9000 bytes of payload. (9122 total, IIRC)
> Ok, modern Procurves are good.  Its unlikely to be this.
> [...]
>> But here's the one I love:
>> -bash-3.2# ethtool -K tso off
>> no offload settings changed

Patrick Geoffray reminded me that typing in the whole command including 
the port might have helped.  I've got to retry this, but I think I 
actually have done this correctly (with all appropriate params) and it 
still failed.

> Hmmm... driver sounds borked if it advertises being able to turn tso 
> on/off and then doesn't let you.
>> I apparently can't control things with ethtool...
> ... smells like the driver.
> [...]
>>>>> I'll go snag the new driver and compile it.  After all: What can it 
>>>>> hurt!
> Any luck with this?  I pulled down the tarball and built it here on a 
> 2.6.9 based machine without incident.  Not RPM format (no .spec file), 
> but fairly painless to build.

Now a task for "later tonight" since I've got a deadline breathing down 
my neck.

Gerry Creager -- gerry.creager at tamu.edu
Texas Mesonet -- AATLT, Texas A&M University	
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983
Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843

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