[TrueNAS SCALE 24.04.x] Adding a USB Serial Port and Assignign a TTY for Login over Serial? How?

Hello,

I’ve attached a USB serial port to my TrueNAS Scale server.

[Mon Sep 23 14:52:19 2024] ch341-uart ttyUSB0: break control not supported, using simulated break
[Mon Sep 23 14:52:19 2024] usb 1-4: ch341-uart converter now attached to ttyUSB0

The docs don’t cover how to configure SCALE to use a USB serial device for the Serial Console under Advanced → Console.

The GUI for setting up the serial console doesn’t actually see the ttyUSB0 device as an option, and I’ve also noticed that there’s no serial-getty service running for it.

On any other linux system, I’d systemctl enable serial-getty@ttyUSB0.service to get the system to activate the serial port, and then add console=ttyUSB0,115200n8 to grub’s kernel command line with an update grub to activate everything.

Even if that worked, I’m pretty sure that wouldn’t magically sync up the GUI. I’m also aware that extra kernel parameters are supposed to be set with a … middleware control tool? I feel really in the weeds with this, but something tells me that the most stable way to get this to work is to be able to set up the serial connection via the GUI … which I can’t do if it doesn’t show me the USB serial port.

I just looked at what I thought was the full grub config, and I don’t even see my full kernel commandline.

vectorsigma /etc/default/grub.d% cat truenas.cfg 
GRUB_DISTRIBUTOR="TrueNAS Scale"
GRUB_TIMEOUT=10
GRUB_DISABLE_RECOVERY="true"
GRUB_CMDLINE_LINUX_DEFAULT="libata.allow_tpm=1 amd_iommu=on iommu=pt kvm_amd.npt=1 kvm_amd.avic=1 intel_iommu=on zfsforce=1 nvme_core.multipath=N"
GRUB_TERMINAL_INPUT="console"
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX=""

EDIT: I found a similar, unanswered question here: TrueNAS Scale 24.04.02 Serial over Lan (SOL)