[gpfsug-discuss] Connecting IBM ESS 3200 to 10 Gb Ethernet

[Jonathan Buzzard]

On 05/06/2023 14:24, Prasad Surampudi wrote:
> 
> Does anyone know if we can connect IBM ESS 3200 to a customer 10 Gb 
> ethernet network? If so what cables  we need to connect it to a 
> CiscoC93180YC-EXswitch? Does it support 100 Gb to 4x10 GB fanout 
> connections?
> 

 From the connecting devices perspective the 4x10Gbps fanout *should* be 
just another 10Gbps connection.

As far as cables go, you could always play it safe and use vendor 
supplied SR transceivers either end.

However why 10Gbps? The switch in question has 48 10/25Gbps ports and 
six 40/100Gbps ports. NVMe flash at 10Gbps is as daft as a brush IMHO.

That said none of that is a guarantee as we currently have Lenovo 
servers with Lenovo SR transceivers in that are refusing to talk to our 
HPE SN3700M (a rebadged Mellanox SN3700M) on a fanout with both QSFP+ 
and QSFP28 transceivers. Crazy thing is I can pull out the Lenovo 
branded transceiver from the Lenovo server and plug into a Cisco X710 
card in a Dell server and get link with the same fibre connection.

Then again the latest firmware for the X722 cards in these Lenovo 
servers still won't work with a mix of DAC and transceiver plugged in, 
they just shut down both ports. Reported that to Lenovo last year, a 
couple of new firmware releases this year still no fix and no warning 
either of the world of pain you could be in for with a firmware upgrade. 
I give Lenovo 0/10 for still not having a huge warning in the changelog 
about that.



JAB.

-- 
Jonathan A. Buzzard                         Tel: +44141-5483420
HPC System Administrator, ARCHIE-WeSt.
University of Strathclyde, John Anderson Building, Glasgow. G4 0NG