Ubuntu Aeotec USB/Serial driver - kernel bug

Hi Folks, I’ve been wrestling this one for a while now-

I’ve HA 2021.7.0.dev w/ ESXI 7 and Ubuntu 20.04 on a HP Microserver (forget which one, not new), using the deprecated Z-wave integration.

My Aoetec z-wave stick has been fine for a year or two but has just stopped working after a reboot of the ESXI platform.

OZW log shows-

Info, Opening controller /dev/ttyACM0
Info, Trying to open serial port /dev/ttyACM0 (attempt 1)
Error, ERROR: Cannot open serial port /dev/ttyACM0. Error code 5
Error, ERROR: Failed to open serial port /dev/ttyACM0

If I build a new VM and install same setup, add the integration, start z-wave - all is fine, hence I’m confident with the USB setup of ESXI, the stick, the key etc.

Something in this VM (which has identical settings to the new one mentioned above) seems to be locking the USB/serial comms but I cant fathom it.

Appreciate any help.

Your log indicates that you lost connection to stick… seems it is not connected to VM. First thing to check is if it is passed through to VM. Do not know why, but it happened several times to me, that after restart of VM or ESXi configuration of connected USB devices was lost - in particular zwave or zigbee sticks. In such case you need to shut down VM, reconfigure it to make sure that stick is connected to this particular VM an start it again… I’m using ESXi 6.0U2, so I’m not sure if this is the same case as for v7… but you can always try.

Now resolved (finally).

Its a Linux kernel issue so others may encounter the same. Upgraded to Ubuntu 21.04 and immediately solved the problem. Kernel v. 5.11.0-18.