[request] USB-Mount with additional SN# as identifier

[dariusaurius]

Hi,

is is possible to add the device-serial-number to the USB mounting configuration? I tried to add it via "XML-Edit" but it gives me an error and proceeds to remove my VM/domain.

I saw a couple tool sets for USB auto-mounts on GitHub, and every one of them had the option to add the additional serial number.

My hope is to replace the mounting via Bus/Device.

Thanks and regards!

[ryecoaaron]

The plugin allows you to use vendor/product id. Is there a reason this isn't working for you? Do you have more than one of an identical device? If you do, are you sure they have unique serial numbers?

[dariusaurius]

yes, they have the same vendor/product but are totally different sticks with different serials. One is a Zigbee-Stick from NabuCase (Home Assistant) the other is a Z-Wave-Stick from Aeotec. Unfortunataly they use the same serial-controller and therefore share the same vendor/product.

I worked around with udev by assigning them a specific tty and adding a serial-device in the XML-Config of the VM. This was the most robust think I could think of, because tty's dont care if there is actual hardware plugged in or not. Identification by device-path would bring me no more advantages, it just ties the sticks to specific ports.

# Rule for specific SkyConnect:
SUBSYSTEM=="tty", ATTRS{serial}=="dcf5fc719cXXXXXXXX162c613ac", SYMLINK+="ttyS11", MODE="0666"

# Rule for specific Aeotec Z-Wave USB:
SUBSYSTEM=="tty", ATTRS{serial}=="2607f1f44aXXXXXXXX9d1cc348", SYMLINK+="ttyS12", MODE="0666"

This comes with the disadvantage that it is only a tty and not a real USB device. Comfort features like the configuration of the Stick are not supported then anymore in the VM.

[ryecoaaron]

I haven't found any xml formatting that virsh leaves in the xml. I find conflicting info on whether virsh even supports serial numbers.

[dariusaurius]

That myth explain why my VM gets deleted, when I add the number, because the config is invalid 🙈

I guess this repo, is doing it in another way: https://github.com/tommyjlong/usb-libvirt-hotplug
It uses this input from the user to identify the correct device:
declare -a stick2=("hassio" "10c4:ea60" "2eba2b499514ed11a6d5b68be054580b")

So basically a search for the serial number is required to get the correct Bus/Device address? What methods could you think off to query the the Bus/Device address, e.g. udevadm?
I could try to help, if you could point me in the right direction.

[ryecoaaron]

That myth explain why my VM gets deleted, when I add the number, because the config is invalid

My VM was never deleted. It just removed the serial element.

So basically a search for the serial number is required to get the correct Bus/Device address? What methods could you think off to query the the Bus/Device address, e.g. udevadm?

lsusb -v has the serial number. I didn't have any problem adding the serial number to the dropdown in the plugin when adding a usb device. That just isn't very useful if the VM's xml won't keep the serial number. Running a script like the one you linked to is about the only way to do this that I know of.

[dariusaurius]

I see... so it was just my stupidity using ChatGPT for once. This hostdev deletes the VM after saving:

   <hostdev mode='subsystem' type='usb' managed='yes'>
      <source>
        <vendor id='0x9876'/>
        <product id='0x5432'/>
        <serial>XXXXXXXX</serial>
      </source>
      <address type='usb' bus='0' port='2'/>
      <startupPolicy>optional</startupPolicy>
    </hostdev> 

lsusb -v is nice. Not sure how you are dealing with dependencies, but lsusb is not installed per default, it's comes with the package usbutils, that's the reason I mentioned udevadm before.

[ryecoaaron]

chatgpt does an ok job most of the time. I just added a usb device with the plugin and then added serial line.

While every one of my OMV systems already has usbutils installed, it wouldn't be hard to add the package as a kvm plugin dependency.