quoted

Any chance you could also send a patch that reads /etc/nvme/hostnqn
for a default hostnqn so that we can have a persistent one?

I'm a tad unclear what is the request? The default hostnqn is buried
inside /dev/nvme-fabrics.  You want nvme-cli to read out the default
hostnqn from /dev/nvme-fabrics and place it in  /etc/nvme/hostnqn?

I think Christoph is requesting that when the user doesn't pass a
hostnqn, nvme-cli will try to read it from a file located in
/etc/nvme/hostnqn (and if this doesn't exist then go ahead without
it). This way, the host can have a persistent hostnqn across reboots
(the driver generates one on module init time).