Limited to 8 LUNs?

[Lex]

I have presented 10 LUNs from storage to my Windows 2019 initiator over RoCEv2, and while each connection is successful, it only sees 8 of the 10 volumes presented to the host from the array. Is this a Starwind Initiator limitation? Any settings I am overlooking which would unlock more volumes?

[yaroslav (staff)]

On the initiator host, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e97b-e325-11ce-bfc1-08002be10318}
expand something that "can be expanded" e.g., 0004 directory. Check MaxNamespaces value (set to something between 1 and 255).
Reboot, and try over again.

[Lex]

Thank you for this guidance, but I don't see MaxNamespaces in the location you specified. If this is something I can create, please let me know if it goes in the root of the 000# folder and the value type (dword, etc)

[yaroslav (staff)]

See under parameters.

[Lex]

Only "BusType" is available under Parameters.

[yaroslav (staff)]

Create the REG DWORD MaxNamespaces under 0003.

[Lex]

Okay, I have done as suggested and the system comes up with the same 8 drives. Please see the attachment and let me know if this is correct.

Must I disconnect all paths and reconnect in order to see the change?

[Lex]

Nope, confirmed that disconnecting all and reconnecting (following registry change + reboot) has no effect on LUNs connected. Still limited to 8.

Code: Select all

StarNVMeoF Controller Application v 2.0.0.672
Our Miniport #2 (ver 2.0 build 672)
HostId 7958DA786AF086D7-A86FE9ADF955F16E, HostName a09-23
        NET_LUID:       0x600800B000000
Connecting to RDMA target at addr 10.3.14.51:4420 from 10.3.14.11 SubNQN=nqn.2010-06.com.purestorage:flasharray.561d839ad7a29cc8 HostNQN=nqn.2008-08.com.starwindsoftware.a09-23 nq=0 qd=0 node=0 core=0...
Controller connected: TargetId = [0]
        numLuns = 8, numIoQs = 96, ioQDepth = 128, numaNode = 0, firstCore = 0
Adding persistent entry for target 0...
Persistent entry for target 0 added

[yaroslav (staff)]

Check also here.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\StarNVMeoF\Parameters (the older place for the registry)
Please try disconnecting all the paths and reconnect too.

[Lex]

The value was not in that location either, but I added it, rebooted, disconnected all paths and reconnected. Unfortunately, there is no change...still 8 LUNs connected out of 10.

[yaroslav (staff)]

Hi,

Sorry for misleading you. Move the DWORD under.../003/Parameters

[Lex]

Alright, THAT did the trick. I now see the 10 LUNs provisioned to the host.

If possible, in future releases, it would be great have this be either dynamic or at least set to a logical limit in line with the underlying operating system. Windows supports 26 lettered volumes by default, with 2 typically in use by default, so a number like 24 is probably a good default with enough headroom so more users don't hit what I hit.

Two questions:
1) You said set MaxNamespaces to something between 1 and 255. Does the number truly not matter or have any correlation to the number of LUNs i want to support >8?
2) Does setting this value utilize more memory or CPU or any other consequence that would be reason not to set it?

Thank you for your quick replies and help.

[yaroslav (staff)]

You are welcome. Sorry for missing the spot for the first two times
This parameter requires the system to lock more resources to the initiator to be ready to serve more connections. That's why we picked the minimum value. I don't think the cap of 24 LUNs per target will break anything (we set it to a higher value several times), so you are good.
For the newest releases, this parameter can be tweaked in UI if UI is available according to the license.