SMB Multi-Channel Not working

reuvygroovy 776 Reputation points
2021-04-12T14:31:05.09+00:00

I have two Windows 2019 Servers. Each server has a 2 x 10Gb Team of adapters grouped together as a single interface. I am transferring a bunch of large ISO files (each between 5-20GB) at the same time from one to the other.

I have checked on the both servers and both command on each return True:
Get-SmbClientConfiguration | Select EnableMultichannel
Get-SmbServerConfiguration | Select EnableMultichannel

But when I copy the above mentioned files from one host to another, when running the command Get-SmbMultichannelConnection I don't see any connections (IPs) from any of these servers (on both servers). I also don't think I am using both adapters since my throughput (which theoretically should be 20Gb usually caps at about 500-600MB/s.

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Windows Server
Windows Server
A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.
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  1. reuvygroovy 776 Reputation points
    2021-04-14T09:05:04.39+00:00

    I have two 10Gb adapters in a Team, so for the 20Gb Team:

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  1. Candy Luo 12,656 Reputation points Microsoft Vendor
    2021-04-14T09:01:37.13+00:00

    Hi,

    Please first make sure the binding for the NIC is set to true for SMB client (MS_client) and SMB server (MS_server).

    The command below should show True under Enabled for both: Get-NetAdapterBinding -ComponentID ms_server,ms_msclient

    After that, make sure the network interface is listed in the output of the following commands: Get-SmbServerNetworkInterface Get-SmbClientNetworkInterface

    If everything looks good there, check the firewall. Make sure SMB traffic is not blocked by firewall. If the network profile is set to Public. This means that SMB is blocked at the firewall by default.

    The following article talks about how to troubleshoot SMB Multichannel issue, you could have a look: SMB Multichannel troubleshooting

    Best Regards,

    Candy

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  2. reuvygroovy 776 Reputation points
    2021-04-14T09:21:09.537+00:00

    No firewall. This is on a LAN.

  3. reuvygroovy 776 Reputation points
    2021-04-14T09:28:29.12+00:00

    What would I be looking for in a traffic trace?

  4. reuvygroovy 776 Reputation points
    2021-04-21T04:44:05.85+00:00

    Working on it. Hope to update soon.