A problem on TCP in High RTT Environment.

[Michael Tuexen]

On 11 Aug 2014, at 21:40, Eggert, Lars <lars at netapp.com> wrote:

> Hi,
> 
> On 2014-8-11, at 21:27, Michael Tuexen <Michael.Tuexen at lurchi.franken.de> wrote:
>> On 11 Aug 2014, at 14:12, Eggert, Lars <lars at netapp.com> wrote:
>>> 544/57/8194 requests for mbufs denied (mbufs/clusters/mbuf+clusters)
>> I guess the above is the problem. The card wants a lot of mbufs...
>> So the problem should go away if you increase the number of mbufs/clusters,
>> which means no requests are denied and you don't experience any performance
>> issue.
> 
> And I have six of those ports in that box...
> 
> So I bump kern.ipc.nmbclusters? Any additional sysctls I should bump?
If I remember correctly, I increased
kern.ipc.nmbufs and kern.ipc.nmbclusters in /boot/loader.conf
After reboot you shouldn't see any denied requests in netstat -m.
Using these setting the card worked fine (for SCTP... ).

Best regards
Michael
> 
> Thanks,
> Lars
>