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© Rakhesh Sasidharan

Elsewhere

FC with Synergy 3820C 10/20Gb CNA and VMware ESXi

(This post is intentionally brief because I don’t want to sidetrack by talking more on the things I link to. I am trying to clear my browser tabs by making blog posts on what’s open, so I want to focus on just getting stuff posted. :)

At work we are moving HPE Synergy now. We have two Synergy 12000 frames with each frame containing a Virtual Connect SE 40Gb F8 Module for Synergy. The two frames are linked via Synergy 20Gb Interconnect Link Module(s). (Synergy has a master/ satellite module for the Virtual Connect modules so you don’t need a Virtual Connect module per frame (or enclosure as it used to be in the past)). The frames have SY 480 Gen 10 compute modules, running ESXi 6.5, and the mezzanine slot of each compute module has a Synergy 3820C 10/20Gb CNA module. The OS in the compute modules should see up to 4 FlexNIC or FlexHBA adapters per Virtual Connect module.

The FlexHBA adapters are actually FCoE adapters (they provide FCoE and/ or iSCSI actually). By default these FlexHBA adapters are not listed as storage adapters in ESXi so one has to follow the instructions in this link. Basically:

1) Determine the vmnic IDs of the FCoE adapters:

2) Then do a discovery to activate FCoE:

As a reference to my future self, here’s a blog post on how to do this automatically for stateless installs.

Totally unrelated to the above, but something I had found while Googling on this issue: Implementing Multi-Chassis Link Aggregation Groups (MC-LAG) with HPE Synergy Virtual Connect SE 40Gb F8 Module and Arista 7050 Series Switches. A good read.

Also, two good blog posts on Synergy:

HP DL360 Gen9 with HP FlexFabric 534 adapter and HP Ethernet 530 adapter and ESXi

That’s a very vague subject line, I know, but I couldn’t think of anything concise. Just wanted to put some keywords so that if anyone else comes across the same problem and types something similar into Google hopefully they stumble upon this post.

At work we got some HP DL360 Gen9s to use as ESXi hosts. To these servers we added additional network cards –

  • HP FlexFabric 10Gb 2-port 534FLR-SFP+ Adapter; and
  • HP Ethernet 10Gb 2-port 530SFP+ Adapter.

Each of these adapters have two NICs each. Here’s a picture of the adapters in the server and the vmnic numbers ESXi assigns to them.

serverIn this picture –

  • vmnic5 & vmnic4 are the HP FlexFabric 10Gb 2-port 534FLR-SFP+ Adapter;
  • vmnic6 & vmnic7 are the HP Ethernet 10Gb 2-port 530SFP+ Adapter; and
  • vmnic0 – vmnic3 are HP Ethernet 1Gb 4-port 331i Adapter (which come in-built into the server);
  • iLO is the iLO port (which I’ll ignore for now).

We didn’t want to use vmnic0 – vmnic3 as they are only 1Gb. So the idea was the use vmnic4 – vmnic7. Two NICs would be for Management+vMotion (connecting to two different switches); two NICs would be for iSCSI (again connecting to different switches).

We came across two issues. First was that the FlexFabric NICs didn’t seem to support iSCSI. ESXi showed two iSCSI adapters but the NICs mapped to them were the regular Ethernet 10Gb ones, not the FlexFabric 10Gb ones. Second issue was that we wanted to use vmnic4 and vmnic6 for Management+vMotion and vmnic5 and vmnic7 for iSCSI – basically a NIC from each adapter such that even if an adapter were to fail there’s a NIC from another adapter for resiliency. This didn’t work for some reason. The Ethernet 10Gb NICs weren’t “connecting” to the network switch for some reason. They would connect in the sense that the link status appears as connected and the LEDs on the switch and NICs blink, but something was missing. There was no real connectivity.

Here’s what we did to fix these.

But first, for both these fixes you have to reboot the server and go into the System Utilities menu.

f9 system utils

Change 1: Enable iSCSI on the FlexFabric adapter (vmnic4 and vmnic5)

Once in the System Utilities menu select “System Configuration”.

system configurationSelect the first FlexFabric NIC (port1).

select flexfabricThen select the Device Hardware Configuration menu.

select device hardwareYou will see that the storage personality is FCoE.

current flex personalityThat’s the problem. This is why the FlexFabric adapters don’t show up as iSCSI adapters. Select the FCoE entry and change it to iSCSI.

new flex personalityNow press Esc to go back to the previous menus (you will be prompted to save the changes – do so). Then repeat the above steps for the second FlexFabric NIC (port 2).

With this change the FlexFabric NICs will appear as iSCSI adapters. Now for the second change.

Change 2: Enable DCB for the Ethernet adapters

From the System Configuration menu now select the first Ethernet NIC (port 1).

select ethernetThen select its Device Hardware Configuration menu.

select device hardware (ethernet)Notice the entry for “DCB Protocol”. Most likely it is “Disabled” (which is why the NICs don’t work for you).

current DCBChange that to “Enabled” and now the NICs will work.

new DCBThat’s it. Once again press Esc (choosing to save the changes when prompted) and then reboot the system. Now all the NICs will work as expected and appear as iSCSI adapters too.

rebootI have no idea what DCB does. From what I can glean via Google it seems to be a set of extensions to Ethernet that provide “hardware-based bandwidth allocation to a specific type of traffic and enhances Ethernet transport reliability with the use of priority-based flow control” (via TechNet) (also check out this Cisco whitepaper for more info). I didn’t read much into it because I couldn’t find anything that mentioned why DCB mattered in this case – as in why were the NICs not working when DCB was disabled? The NICs are connected to an HP 5920AF switch but I couldn’t find anything that suggested the switch requires DCB enabled for the ports to work. This switch supports DCB but that doesn’t imply it requires DCB.

Anyhow, the FlexFabric adapters have DCB enabled by default which is probably why they worked. That’s how I got the idea to enable DCB on the Ethernet adapters to see if it makes a difference – and it did! The only thing I can think of is that DCB also seems to include a DCBX (Data Centre Bridging Exchange) protocol which is about discovering peers, discovering mismatched configuration etc – so maybe the fact that DCB was disabled on these adapters made the switch not “see” these NICs and soft-disable them somehow. That’s my guess at least.