I recently ran into an issue on an Ubuntu 24.04 server where the system would intermittently hang and become unresponsive. Checking /var/log/syslog, it seems the onboard Intel network card was the problem.

May 14 01:38:09 server-1 kernel: e1000e 0000:00:1f.6 eno1: Detected Hardware Unit Hang:
...
May 14 01:38:25 server-1 kernel: workqueue: e1000_print_hw_hang [e1000e] hogged CPU for >13333us 4 times, consider switching to WQ_UNBOUND

This repeats every 2 seconds, filling the logs and hogging CPU time. The NIC in question is using the e1000e driver for the onboard Intel Ethernet controller. This is a known issue with certain Intel NICs and the e1000e driver. The kernel repeatedly reports a “Hardware Unit Hang” when the NIC’s transmit queue stalls. Apparently, it is more often see this after the system has been up for a while, usually under I/O or network load. Power-saving features and offloads like ASPM and TSO seem to trigger or worsen it.

Fixing e1000_print_hw_hang

1. Disable TSO (TCP Segmentation Offload)

This stops the NIC from offloading TCP segmentation — which can misbehave on this driver.

sudo ethtool -K eno1 tso off

But this won’t persist after reboot, so we’ll make it stick with a systemd service…

Make TSO Setting Persistent with systemd

Create a service file:

sudo nano /etc/systemd/system/disable-tso.service

Paste this in:

[Unit]
Description=Disable TSO on eno1
After=network.target

[Service]
Type=oneshot
ExecStart=/sbin/ethtool -K eno1 tso off
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target

Enable it:

sudo systemctl daemon-reexec
sudo systemctl enable disable-tso.service

Optional: start it now without rebooting:

sudo systemctl start disable-tso.service

2. Disable PCIe ASPM via GRUB

Edit the GRUB config:

sudo nano /etc/default/grub

Find this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

And change it to:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=off"

Then update grub:

sudo update-grub

After these changes, the e1000e driver should became stable again.