Converged Networking without RDMA enabled Network Cards?

Question

I'm looking at a problem we've had appear over the last 12 months or so on a Hyper-V 2016 cluster running on DL360 Gen 9 servers, where all of a sudden we are getting event ID 252 and message:

"Memory allocated for packets in a vRss queue (on CPU 0) on switch 42AF3F0F-F128-4ADF-961E-2654E5156471 (Friendly Name: 10G Converged Switch) due to low resource on the physical NIC has increased to 256MB. Packets will be dropped once queue size reaches 512MB."

Shortly after this the iSCSI CSV that is "owned" by the node starts throwing errors with Shared I/O volume paused and everything starts shifting around.

I thought I'd go right back to the beginning and check everything over and I noticed here that Microsoft says "To use Converged NIC technology, the certified network adapters in your servers must support RDMA".

I went to the quickspecs for my NIC and I can't see any mention of "RDMA over Converged Ethernet (RoCE)" it. Nevertheless, it does work (most of the time!)

Is anybody else using non-RDMA adapters with Microsoft converged networking?

Thank in advance for any help!

Answer 1

Hi,

--"Memory allocated for packets in a vRss queue (on CPU 0) on switch 42AF3F0F-F128-4ADF-961E-2654E5156471 (Friendly Name: 10G Converged Switch) due to low resource on the physical NIC has increased to 256MB. Packets will be dropped once queue size reaches 512MB."

Please try to increase the "Receive buffers" in the physical NIC on the Hyper V hosts to 256 and test if the issue could be resolved, if it still not work, increase to 1024, check the result.

https://social.technet.microsoft.com/Forums/windowsserver/en-US/ef5a9d33-a50a-47b0-aeeb-1f21422ba992/event-id-252-hypervvvmswitch?forum=winserverhyperv

https://social.technet.microsoft.com/Forums/ie/en-US/35b3a7f2-b91f-4b4c-a570-651943223d64/memory-allocated-for-packets-in-a-vrss-queue?forum=winserverhyperv

Thanks for your time!
Best Regards,
Anne

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

If the Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.