FreeBSD iscsi target

[Slawa Olhovchenkov]

On Thu, Jul 03, 2014 at 08:39:42PM -0700, Kevin Oberman wrote:

> >
> > In real world "Reality is quite different than it actually is".
> >
> > http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6500-series-switches/white_paper_c11-696669.html
> >
> > See "Packet Path Theory of Operation. Ingress Mode".
> >
> >
> Yep. It is really crappy LAGG (fixed three-tupple hash... yuck!) and is
> really nothing but 4 10G Ethernet ports using a 40G PHY in yhe 4x10G form.
> 
> Note that they don't make any claim of 802.3ba compliance. It only states
> that "40 Gigabit Ethernet is now part of the IEEE 802.3ba standard." So it
> is, but this device almost certainly predates the completion of the
> standard to get a product for which there was great demand. It's a data
> center product and for typical cases of large numbers of small flow, it
> should do the trick. Probably does not interoperate with true 80-2.3ba
> hardware, either.
> 
> My boss at the time I retired last November was on the committee that wrote
> 802.3ba. He would be a good authority on whether the standard has any vague
> wording that would allow this, but he retired 5 month after I did and I
> have no contact information for him. But I'm pretty sure that there is no
> way that this is legitimate 40G Ethernet.

802.3ba describe only end point of ethernet.
ASIC, internal details of implemetations NICs, switches, fabrics --
out of standart scope.
Bottleneck can be in any point of packet flow.
In first pappers of netmap test demonstarated NIC can't do saturation
of 10G in one stream 64 bytes packet -- need use multiple rings for
transmit.

I think need use general rule: one flow transfer can hit performance
limitation.