hwe kernel on 18.04: how did it get here and can I remove?

**undecidable** · April 11th, 2019

I am running a clean install of Xubuntu 18.04 (from xubuntu-18.04-desktop-amd64.iso)
on 2 laptops (one with nvidia graphics, one with intel graphics) and on 3 VMs.

apt list --installed linux-image* on my laptops gives me:

linux-image-4.15.0-46-generic/bionic-updates,bionic-security,now 4.15.0-46.49 amd64 [installed,auto-removable]
linux-image-4.15.0-47-generic/bionic-updates,bionic-security,now 4.15.0-47.50 amd64 [installed,automatic]
linux-image-4.18.0-16-generic/now 4.18.0-16.17pop0~18.04.1 amd64 [installed,local]
linux-image-4.18.0-17-generic/bionic-updates,bionic-security,now 4.18.0-17.18~18.04.1 amd64 [installed,automatic]
linux-image-generic/bionic-updates,bionic-security,now 4.15.0.47.49 amd64 [installed,automatic]
linux-image-generic-hwe-18.04/bionic-updates,bionic-security,now 4.18.0.17.67 amd64 [installed,automatic]

(I keep one old vsn of every kernel just in case)

1. I did not ask for or install the hwe kernel, why is it installed?
It is installed on both my laptops but not my VMs?!

2. Install instructions for the hwe kernel say:

sudo apt install --install-recommends linux-generic-hwe-18.04 xserver-xorg-hwe-18.04

but while linux-generic-hwe-18.04 is installed xserver-xorg-hwe-18.04 is not.
How is this possible?

uname -a shows on both laptops:

4.18.0-17-generic #18~18.04.1-Ubuntu SMP

so I am running the hwe kernel, so why does it work without the corresponding xserver-xorg-hwe-18.04 ?

3. (How) can I safely uninstall the hwe kernels and just use the standard ones?
I can select the standard kernels from grub and boot to them ok.

**ajgreeny** · April 11th, 2019

When did you install the system, and did you use the 18.04.2 point release, or the original 18.04 or 18.04.1 version?

The two latter versions I mention above used the original 4.15 kernel series and only with the 18.04.2 point version did you get the 4.18 kernel series which would update itself automatically, along with other system upgrades; that may be why you are seeing the hwe kernels in your system.

Before you start uninstalling any of those 4.18 kernels please show us the output of

Code:

dpkg -l linux-generic

which will allow us to see which kernels, if any, can be safely removed.

**undecidable** · April 11th, 2019

Thanks for the fast response.

I installed the original 18.04, from the xubuntu-18.04-desktop-amd64.iso medium
though over time it has upgraded to 18.04.2.
From lsb_release -a

No LSB modules are available
Distributor ID: Ubuntu
Description: Ubuntu 18.04.2 LTS
Release: 18.04
Codename: bionic

The output of dpkg -l linux-generic

ii linux-generic 4.15.0.47.49 amd64 Complete Generic Linux kernel and headers

**ajgreeny** · April 11th, 2019

The output you show from dpkg -l linux-generic is exactly what I get on my Xubuntu 18.04 also installed from the original .iso image but I do not have any 4.18 kernels installed in my system.

There does not appear to be any reason for the update system to have installed the 4.18 kernel series so I wonder if you have added it yourself to overcome a problem that you had at some point in the past.

However, once again, before removing any kernels let's see the output of

Code:

dpkg -l linux-image*

just to see the full list of those installed at present.

**undecidable** · April 11th, 2019

No, I did not have any problem
that caused me to manually install the hwe kernel.
Most of my problems get solved by coffee, not kernels.

The output of dpkg -l linux-image*

un linux-image <none> <none> (no description available)
rc linux-image-4.15.0-4 4.15.0-45.48 amd64 Signed kernel image generic
ii linux-image-4.15.0-4 4.15.0-46.49 amd64 Signed kernel image generic
ii linux-image-4.15.0-4 4.15.0-47.50 amd64 Signed kernel image generic
ii linux-image-4.18.0-1 4.18.0-16.17pop amd64 Signed kernel image generic
ii linux-image-4.18.0-1 4.18.0-17.18~18 amd64 Signed kernel image generic
ii linux-image-generic 4.15.0.47.49 amd64 Generic Linux kernel image
ii linux-image-generic- 4.18.0.17.67 amd64 Generic Linux kernel image
un linux-image-unsigned <none> <none> (no description available)
un linux-image-unsigned <none> <none> (no description available)
un linux-image-unsigned <none> <none> (no description available)
un linux-image-unsigned <none> <none> (no description available)
un linux-image-unsigned <none> <none> (no description available)

This is similar to the output of
apt list --installed linux-image*
shown in the original post.

However one thing suddenly does stand out, the "pop" in the line:

ii linux-image-4.18.0-1 4.18.0-16.17pop amd64 Signed kernel image generic

I mentioned the hwe kernels are only on the laptops (both system76) and not the VMs.
This is a clean install from Ubuntu medium
but i did install of course the system76-driver.
Now PopOS is the system76 OS, so I wonder if it is possible that the system76-driver updating
caused the install of the hwe kernels
but not the linux-generic-hwe-18.04 xserver-xorg-hwe-18.04 ?

**undecidable** · April 11th, 2019

In fact that may be the answer.
Just checked the dependencies
Output of

Code:

 aptitude show system76-driver

Package: system76-driver
Version: 19.04.7~1553705208~18.04~446bbf4~dev
State: installed
Automatically installed: no
Priority: extra
Section: utils
Maintainer: System76, Inc. <dev@system76.com>
Architecture: all
Uncompressed Size: 457 k
Depends: python3:any (>= 3.4~), dconf-gsettings-backend | gsettings-backend, at, gir1.2-gtk-3.0,
gir1.2-notify-0.7, gnome-shell-extension-system76-power, linux-generic (>= 4.18) |
linux-generic-hwe-18.04, pm-utils, python3-dbus, python3-evdev, python3-gi, python3-systemd,
system76-dkms, system76-firmware-daemon, system76-io-dkms, system76-power, system76-wallpapers,
xbacklight

So, it seems an update to the system76 driver caused the install of the hwe kernel.
Doesn't explain how i missed it.
maybe just age and infirmity

**ajgreeny** · April 11th, 2019

Good news that at least we now know how and why it happened!

Please mark as SOLVED from the Thread Tools menu up-top if this is now solved to your satisfaction.
It is a great help to other users searching the forum.