Please see the following user manual Mellanox ConnectX-4/ConnectX-5 NATIVE ESXi Driver for VMware vSphere 6.5.
Please see section 3.1.4 Priority Flow Control (PFC) :
Karen, Thank you for the reply.
Can you tell me what is Mellanox's recommended configuration if there is just 1 traffic flow? My connectx-4 cards are direct connected between two servers and used only to connect the iser initator to the iser target. There is no other traffic on these nics. I have seen references to creating a vlan and assigning it to one of the priority queues yet none of this applies to my scenario. Should i just run global pause?