What is the issue?

After the deployment and configuration of Dell EMC Storage Spaces Direct Ready nodes (following the deployment guidance at http://en.community.dell.com/techcenter/extras/m/white_papers/20444544.

This can be verified by running show interfaces tengigabitethernet x/y pfc detail.

TOR1#show interfaces tengigabitethernet 1/5 pfc detail

Interface TenGigabitEthernet 1/5

     Admin mode is on

     Admin is enabled, Priority list is 3

     Remote is disabled

     Local is enabled, Priority list is 3

     Oper status is init

     PFC DCBX Oper status is Down

     Reason: Waiting for Peer

     State Machine Type is Symmetric

     TLV Tx Status is enabled

     PFC Link Delay 65535 pause quntams

     Application Priority TLV  Parameters :

     --------------------------------------

     FCOE TLV Tx Status is enabled

     ISCSI TLV Tx Status is disabled

     Local FCOE PriorityMap is 0x8

     Local ISCSI PriorityMap is 0x0

     1581 Input TLV pkts, 8649 Output TLV pkts, 121 Error pkts, 4495543 Pause Tx pkts, 374345 Pause Rx pkts

     0 Input Appln Priority TLV pkts, 0 Output Appln Priority TLV pkts, 0 Error Appln Priority TLV Pkts

Where is the issue?

As a part of the deployment guidance for Dell EMC Storage Spaces Direct Ready Nodes, for infrastructures that use RoCE v2 for RDMA using Mellanox CX4 LX adapters, we recommend disabling DCBX willing globally in the host OS and setting network adapter DCBXMode to Host in charge. With this configuration, there is no down stream entity that is exchanging the DCBX information with the Dell EMC networking switch and therefore the DCBX operational status will be shown as down on the server facing ports.

Resolution or Workaround 

This is not a showstopper or an issue of concern. This is working as expected.