Need to attach USB device to CentOS5 VM, device not showing up

[ovjc]

Hello, I have an old system that does just one specific job where I need a one-wire controller. We had this VM working on ESXI with the one-wire controller attached as usb devioce to the machin (not passthrough) and this worked flawlessly. Now I moved this system to PVE and I struggle to get the 1wire controller detected inside the VM.
I added it as USB device as mapped device, via vendor id, and via port, but it never shoewd up. It does not matter whether I do this before or after turning on the VM.
I added the virtio stuff to the centos5 ramdisk, but I am not sure whether this also includes the usb drivers, I am not that familiar with the virtio stuff.
I also tried to pass the entire controller through as PCI device, but then the VM did not boot at all and I also needed to reboot PVE to get the usb controller "back".

(No, we cannot easily upgrade this VM to something newer as the software components used do not exist or have chenged a lot and yes this VM is in a secured VLAN and does nothing which is security relevant).

Any advice what I am missing here?

 

[mfederanko]

Can you provide the output of lsusb -vt and the vm config(s) (qm config <VMID>) you tried.
If you passed the device through with a resource mapping [0] please give the output of pvesh get /cluster/mapping/usb/<mapping name>
Is there anything in the system logs (host and guest) something like "usb 3-1: new full speed USB device" or similar?

[0]: https://pve.proxmox.com/pve-docs/pve-admin-guide.html#resource_mapping

 

[ovjc]

I will do so next week, sorry, I had other problems meanwhile...

 

[pulipulichen]

If the USB device already appears in the Proxmox UI when you click Add → USB Device, then the host side is likely detecting it correctly.

One thing you might want to check is the USB controller type used by the VM.

In Proxmox (which uses QEMU underneath), USB passthrough can use either an xHCI (USB3) controller or an EHCI/UHCI (USB2/USB1) controller depending on the settings.

Older systems like CentOS 5 (kernel 2.6 era) often do not support xHCI, so if the device is attached through a USB3 controller it may simply not appear inside the guest.

When adding the device in the Proxmox UI, try unchecking "Use USB3" so the VM uses the older USB2 controller instead (see screenshot). VMware typically exposes EHCI/UHCI controllers by default, which is why the same guest might detect the device there but not under Proxmox.



It might be worth testing with USB3 disabled to see if the device shows up inside the VM (lsusb / dmesg).

 

[ovjc]

Hello all, I now managed to run the old software on a current Ubuntu System, where the USB device is detected correctly. Sadly, I cannot test this USB3 issue any more, but it might well be the reason. Althopugh I think I disabled that once and it did not help. But the solution now is better and safer, sop we can close this thread. Thank you all for helping.