A problem on TCP in High RTT Environment.

[hiren panchasara]

On Mon, Aug 11, 2014 at 12:59 PM, Michael Tuexen
<Michael.Tuexen at lurchi.franken.de> wrote:
> 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

I believe, you just need to set kern.ipc.nmbclusters (max mbuf
clusters allowed) and kern.ipc.nmbufs (max mbufs allowed) should be
adjusted based on that.

cheers,
Hiren