1) Further thoughts - in my case with nvme module built in to kernel,
parameters can be set using kernel boot command line.
2) Also this may be useful, I found this tidbit from 2017 in case your
hardware has this:
ommit 07fbd32a6b215d8b2fc01ccc89622207b9b782fd
Author: Martin K. Petersen <martin.peter...@oracle.com>
Date: Fri Aug 25 19:14:50 2017 -0400
nvme: honor RTD3 Entry Latency for shutdowns
If an NVMe controller reports RTD3 Entry Latency larger than
shutdown_timeout, up to a maximum of 60 seconds, use that value to set
the shutdown timer. Otherwise fall back to the module parameter which
defaults to 5 seconds.
