Hi,

On Sat Aug 16, 2025 at 3:20 PM CEST, Keith Busch wrote:
> On Sat, Aug 16, 2025 at 01:40:44PM +0200, Diederik de Haas wrote:
>> I have a Samsung 970 EVO 2TB SSD and I see these kernel warnings:
>
> ... 
>  
>> I wonder if something can be done to fix those warnings.
>
> Are you talking about this message?
>
>    nvme nvme0: missing or invalid SUBNQN field
>
> You can't do anything about it, but I wouldn't worry about it either.

That's indeed one of them; good to know it's not to worry about.

> If you want to see what the driver is reacting to, you can check the
> subnqn from command line:
>
>   # nvme id-ctrl /dev/nvme0 | grep subnqn
>
> It'll probably be all zeros. The field has been required by spec, but
> the driver tolerates ones that don't implement it.

root@nanopi-r5s:~# nvme id-ctrl /dev/nvme0 | grep subnqn
subnqn    :

So it seems to be just empty?

> It's just a message that the device isn't spec compliant, but
> otherwise perfectly operational.

But still worthy of a warning (instead of info) msg?

The other kernel warning is this:

  nvme nvme0: using unchecked data buffer

The SUBNQN message appears every time, this one appears often, but not
always.

When researching this/these issues, I discovered the nvme-cli package
(with the nvme command) and via its manpage I found this command:

  nvme get-feature /dev/nvme0 -f 3

I didn't even know NVMe's had namespaces, but this didn't look good:

  The namespace or the format of that namespace is invalid(0x200b)

... without actually understanding what it means and/or what its
consequences are. It could be harmless and/or normal though.

Cheers,
  Diederik