[ofa-general] link width problem of Qlogic 9024 unmanaged switch

[Yicheng Jia]

Hi,

I am running into a performance issue while I am doing OpenSM restart test 
with Qlogic 9024 24-ports unmanaged switch. In my test environment, 5 
nodes with Mellanox HCAs directly connect with the switch. During each 
test iteration, all nodes reboot and then OpenSM starts to initiate the 
subnet.

The problem I experience is that some time during OpenSM initiates, some 
ports are reporting 1x link width (I turn on debug option of OpenSM), thus 
the data transfer performance drops down significantly. I believe it's not 
cable/physics connection issue because the 1x link width port randomly 
occurs in different ports, and if I use Flextronics unmanaged switch, the 
problem is gone.

I am wondering if anyone experiences the same problem before, any hint of 
how to fix it?

Thanks!

Yicheng Jia



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