Serial port on a VM, how to check setting?

[DaGerba]

Hi,

here http://forum.proxmox.com/threads/2568-Serial-ports-on-a-VM I found a way to link a physical serial port to a VM using

qm set 107 -serial /dev/ttyS0

That worked, but one morning I found out, it didn't any more. Does anybody know how I can check, if this setting is still active?

Thanks for your advices!

Greetings,
Michael

 

[wolfgang]

Hi,
you can use for this propose the Moritor Tab on the GUI.

VM -> Monitor Tab
info chardev

 

[DaGerba]

Thank you for your reply. That's exactly what I was looking for.

 

[DaGerba]

Hi again,

Just if there is anyone interested:
if you linked a serial port to a VM and want to change it to another one, you first have to disconnect the link with

qm set <VMID> -delete serial0

 

[Adam Koczarski]

Is there any way to do this without rebooting the VM? I'd like to migrate a production VM to another node so I can reboot the first node after upgrading Proxmox. Proxmox won't migrate the VM due to the associated serial port and I can't remove it without rebooting the VM. Kind of painted into a corner.

 

[vmanz]

Hi Adam,

As always on virtualisation there is a solution with network devices. Like USB-over-LAN there are Serial-over-LAN devices available (roundabout 25 years).

I know so called serial device server from a DEC installation. A Server is connected to the network an those device servers are the linked to serial connected terminals and printers https://en.wikipedia.org/wiki/DECserver. Maybe you get some cheap now. Be aware of the needed port speed and some DECserver need to boot via tftp if they come without boot rom.

At a research few years ago I found are even modern serial device server available fpr measureing an machine steering e.g. at Wieseman&Theis https://www.wut.de/

 

[Adam Koczarski]

Hi vmanz,

Thanks for you reply. Yes, I'm familiar with these devices. I've converted my VMware cluster at home to Proxmox over the last 2 weeks. The requirement for a serial port on a node is for an RF home automation device. Not really worth the trouble or cost of procuring a network serial device. VMware allowed me to migrate the Linux VM used for my home automation system, it just disabled the port in the process. If the move was long term I just movde the serial device to the other host and checked a box to get the serial port running again. Under Proxmox it looks like I have to reboot the VM once to remove the port, then migrate, then reboot the VM again to get the serial port back on the other node. This Linux system also hosts some websites so I was hoping for an easy solution which would enable me to keep the websites up full time. No big deal....