StarWind Software

Hi Team,

We are getting the below error message while connecting NVMe Namespace throught TCP protocol.

StarNVMeoF_Ctrl.exe insert_tcp 192.168.10.247:4420 192.168.10.169 nqn.1992-05.com.wdc.openflex-data24-usalp03922qa0030:nvme.1 SW1 7 16StarNVMeoF Controller Application v 1.9.0.519
Our Miniport #3 (ver 1.9 build 500)
HostId 0xF4E6155881933F39-CD7F0A8F02457586 - HostName WIN-7UE6DQLR44E
NET_LUID: 0x6008007000000
Connecting to TCP target at addr 192.168.10.247:4420 from 192.168.10.169 SubNQN=nqn.1992-05.com.wdc.openflex-data24-usalp03922qa0030:nvme.1 HostNQN=SW1 nq=7 qd=16 core=0...
STAR_NVMEOF_IOCTL_TARGET_ADD request failed (err 55)!
ConnectController() failed

The same connection is working with RoCE because of the default MDTS value. In RoCE we use default MDTS as 128 but in TCP mode we set default MDTS as 32.
Looks like Starwind having a restriction on a minimum expected MDTS value of the controller which could be either 64K or 128K. The initiator/host must comply with the MDTS advertised by the target/controller.

Could you please let us know why would have such an expectation?

That's a good question!
StarWind NVMe-oF Driver parameters can be altered by editing the corresponding registry keys.
The driver must be restarted to apply new parameter values.
The MaxTransfer Length is set to 64K by default.
You can tweak it in the registry HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\StarNVMeoF\Parameters.

Thank you for your response.
Please let me know the parameter which I need to add to change the maxtransfer length.
I am unable to see the parameter setting on my current machine on the following path - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\StarNVMeoF\Parameters

Thanks for your update. Can you please try creating the registry key?

I have created the following parameter "MaxTarnsferLength" on the registry editor under - HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\StarNVMeoF\Parameters with the default value as "32". After this i tried restarting the starwind service and a host reboot.
Even after rebooting the host i am unable to establish a connection with TCP protocol.
Please confirm me the register key and the value?

Can you please try 64?