[NCLUG] Networking Issue

[Matt Kassawara]

Do both variants of configuration A have the same problem?  Do any of the
switches in question indicate the reason for discards?  Did you configure
end-to-end support for jumbo frames?  Can you provide more details on "10g
mesh" between the 5412s?


On Mon, Aug 5, 2013 at 5:14 PM, Michael Coffman
<coffman at ftc.avagotech.com>wrote:

>
> I don't do networking and our corporate networking group has been cut so
> thin, they don't do much networking anymore either :(
>
> This is not a linux problem, but I know there are folks on this list that
> have deep networking experience.  I'll try to describe the problem as best
> as I can in ascii.
>
> *NA = NetApp
> *CS = Compute Server
>
> #----  A
> NA -10g-> hp5412(a) -10g mesh-> hp5412(b) -1g-> CS
> NA -10g-> hp5412(a) -10g mesh-> hp5412(b) -4g trunk-> hp2500 -1g-> CS
>
> o The read path to the compute server is very slow 20-30MB/s
> o The write path to the NetApp is close to wire speed 110-130MB/s
> o The hp5412(b) switch is having thousands of discards at the port to the
>   CS system
> o Enabling flow control on all the switches on the mesh almost
>   completely eliminates the discards and increases read performance, but
>   hurts write performance
> o Reversing the flow above does not have the same performance problems
> o Reversing the flow above does not cause discards on hp5412(a)
>
> #---- B
> NA -10g-> hp5412(a) -10g mesh-> hp5412(b) -10g-> hp5800 -1g-> CS
>
> o The above scenario has no performance issues.
> o Still seeing discardson hp5412(b) due to other traffic on the switch
>
> #---- C
> NA -10g-> hp5412(a) -1g-> CS
> NA -10g-> hp5412(a) -1g-> hp2500 -1g-> CS
>
> o The above scenario works fine.
> o The hp5412(a) is not seeing the discards that hp5412(b) does.
>
> Any ideas on how to go about trouble shooting this?
>
> I am not looking for free answers to this problem here, I would be glad to
> talk to someone about doing some network consulting.  Also any pointers to
> a networking consultant/guru would be greatly appreciated.
>
> Thanks.
> -MichaelC
> ______________________________**_________________
> NCLUG mailing list       NCLUG at lists.nclug.org
>
> To unsubscribe, subscribe, or modify
> your settings, go to:
> http://lists.nclug.org/**mailman/listinfo/nclug<http://lists.nclug.org/mailman/listinfo/nclug>
>