Strange issue with scp performance

[Achilleas Mantzios]

On 01/10/2016 03:55, John-Mark Gurney wrote:
> Achilleas Mantzios wrote this message on Wed, Sep 28, 2016 at 13:26 +0300:
>> We have a weird situation here. We just made a clone of a virtual image running Linux and sent it over to some could provider. The problem is that the scp performance to *many* hosts in our office
>> center has worsened considerably, including one freebsd box.
>>
>> In this freebsd box I run also a jail, and a linux ubuntu image with bhyve. The crazy thing here is that :
>>
>> 1) scp from the original (local office center) linux image to the host FreeBSD, its jailed FreeBSD and its bhyve linux is 2.7 MB/s
>> 2) scp from the cloud linux image to the host FreeBSD is slow (~300KB/s)
>> 3) scp from the cloud linux image to the above FreeBSD's jail is slow(~300KB/s)
>> 4) scp from the cloud linux image to the above FreeBSD's bhyve ubuntu is fast(~1->1.5MB/s)
>>
>> What can cause this behavior?
>>
>> PS
>> Please answer to me directly as I am not subscribed to -net.
>> Thanks a lot for any ideas.
> I worked on this last year a bit, but was never able to track it down.
>
> It may be an issue w/ internal SSH's buffering not growing properly to
> handle the latency.
>
> I posted some info on the wiki about this:
> https://wiki.freebsd.org/SSHPerf

Thanks tons!
In this case of mine, just playing around with HPN:

HPNDisabled no
HPNBufferSize 8192

in sshd_config was enough to bring it on par with linux.

>


-- 
Achilleas Mantzios
IT DEV Lead
IT DEPT
Dynacom Tankers Mgmt