Proxmox node hangs – detected Hardware Unit Hang

We have had two instances of one of our Proxmox nodes hanging and upon insepecting /var/log/syslog we observed the following error before the crashes:

enp0s31f6: Detected Hardware Unit Hang proxmox

To solve this we followed the instructions by Jarek Hartman here.

Run the following commands in the terminal:

apt-get install ethtool
ethtool -K enp0s31f6 tx off rx off
ethtool -k enp0s31f6

You should see that rx-checksumming and tx-checksumming are turned off. Note that these values are not persisted.

nano /etc/network/if-up.d/ethtool2

Paste the following in that file and save:


ethtool -K enp0s31f6 tx off rx off
chmod 755 /etc/network/if-up.d/ethtool2
ethtool -k enp0s31f6

You should now see that rx and tx checksumming is turned off.

Fingers crossed Proxmox will no longer hang.