SMB Multichannel - has anyone got it working?

[Kgeee]

MacOS supports SMB Multichannel out of the box. Does this also work connecting via SMB to another mac?

When running smbutil multichannel -a I get Multichannel ON: no. This is between a Mac Mini 2018 and a Macbook Pro 16" M1 Max. One mac uses a Sonnet Twin 10GbE and the other mac uses two bonded Thunderbolt 1Gbe Ethernet adaptors. Both are bonded interfaces, and the Unifi switch is set up for link aggregation. When running two concurrent iPerf3 tests on two separate ports, I get 2GbE speed. But running a single test, I only get around 1 GbE speed which confirms multichannel isn't working.

The Sonnet 10 Gbe adaptor is capable of Server Side Scaling. Not sure about the Apple Ethernet adaptor, but probably not. Not sure if this plays a role. Or maybe it's the CPU not being fast enough? Not sure how to troubleshoot. There is very little information out there about SMB multichannel and mac computers.

 

[Dameatball]

Hi- I've been able to get it to work. I'm not sure I totally follow your setup; LAG should be turned off to use multi channel but I may missing a variable/not understanding your hardware in this scenario.

Anyway I have it setup between a mac mini and an unraid machine. These three lines enable multi channel, specifically only for your wired connections (if you have wifi on as well it would only be for redundancy in this scenario). It's just a couple lines in your nsmb.conf file, you can read here

 

[Dameatball]

sorry please disregard my previous note. My understanding is SMB MC between mac's is screwed up. My analogy was between a Mac and Linux. It didn't occur to me at the time that it wouldn't work out of the box between two mac's but leave it to apple...