[geeks] Well, THAT was a setback

[Phil Stracchino]

On 01/17/10 19:12, Patrick Finnegan wrote:
> On Sunday 17 January 2010, Phil Stracchino wrote:
>> On 01/17/10 18:29, Patrick Finnegan wrote:
>>> On Sunday 17 January 2010, Phil Stracchino wrote:
>>>> I've heard people talk about the Linux TCP stack falling down
>>>> under heavy load, but never had it happen to me.  Until today.
>>>
>>> What hardware, and what distro/kernel?
>>
>> Linux babylon5 2.6.32-gentoo-r1 #9 Sat Jan 16 13:49:53 EST 2010 i686
>>  AMD Athlon(TM) XP 2400+ AuthenticAMD GNU/Linux
>>
>> Asus A7V333 motherboard, 3Com 3C905B PCI Ethernet at present.
> 
> 100 Mbps ethernet? Really?  I haven't touched a 3C905x in many years...
> 
> If you're going to try to push enough data to stream to an LTO (any 
> generation) tape drive, I'd strongly recommend GbE between the client 
> and server.  If you're caching to a disk first, then I guess 100Mbps may 
> be reasonable.

Unfortunately I have neither a spare GigE adapter nor a GigE switch at
the moment.  Now, that said, if I get a dedicated machine set up to host
the tape drive, I could set up a direct point-to-point GigE connection
to it from the main server.

> You said that you have an EEPro 100 in another thread... I'd try that, 
> or an E1000 or similar (the desktop adapters are really cheap, and will 
> still be much faster than your 3c905 even though they won't quite reach 
> 1Gb) before you assume that Linux was the problem.  I guarantee that the 
> Linux TCP stack can handle >100Mbps just fine.  We've been doing GbE 
> compute clusters at work for a while, and have started doing 10GbE 
> clusters last year, all on Debian and RHEL, and we don't see problems 
> that aren't related to a driver/card/cable/network issue.

Useful to know.


-- 
  Phil Stracchino, CDK#2     DoD#299792458     ICBM: 43.5607, -71.355
  alaric at caerllewys.net   alaric at metrocast.net   phil at co.ordinate.org
         Renaissance Man, Unix ronin, Perl hacker, Free Stater
                 It's not the years, it's the mileage.