Kubuntu Forums - Kubuntu Forums .Net

Subvolume won't delete

oldgeek — Mon, 20 Jul 2026 01:48:07 GMT

Awhile ago I had to revert to a pprevious setup due to a problematic upgrade. The recovery went well, but the process left the previous @ subvolume (which I renamed @_new) as a lingering subvolume in a group which includes @, @home, and a swap file. I've tried to delete @_new, both using the command line as well as Oshluvr's script for Dolphin, but no luck. I'm notified that the subvolume has been deleted, but it hasn't bee, I suspect this might be a problem of heirarchy, but since I am by and large ignorant of the structure of btrfs, I have no idea what to do. Any help would be appreciated.

[Software]Skilled Study of Kubuntu 26.10 Stonking Stingray

NoWorries — Sun, 19 Jul 2026 11:14:23 GMT

I was able to download 26.10 (Stonking Stingray) from the site
https://cdimage.ubuntu.com/kubuntu/releases/26.10.

Kubuntu 26.10 is currently under active development and has not yet reached its final, stable release (expected in October 2026).

I got my 26.10 iso on the 3rd June 2026. I have not had any problems with it. My current Info Center is shown below.

I hope this encourages you to try this new system. From the name it has, I am expecting to see a large and impressive system.

All the very best to those on this forum who are willing to give this new system some skilled study.

What is the project's philosophy with regard to vulnerability management?

gordonmessmer — Sat, 18 Jul 2026 19:52:03 GMT

I'm working on a conference talk in which I will discuss the trade-offs inherent to long term releases.

Specifically: distributing software for a longer period than it is maintained upstream is very labor intensive, and different long-term systems approach the problem in different ways. RHEL starts with Fedora but removes ~90% of the packages and features in order to reduce the labor costs over the life of a release. Ubuntu similarly starts with Debian but splits repositories into a small "main" repo component that they promise to maintain and a large "universe" component that they document as merely a snapshot for which they do not promise any updates. Debian is probably effectively similar to Ubuntu, but they don't divide their repo the same way so it's hard to make any clear statements about user expectation of patch coverage over the distribution.

I am curious about how the maintainers of systems derived from Ubuntu LTS releases think about security risks and patch coverage.

Are there any packages in "universe" that are used in a default installation of your desktop? Do you monitor those packages for new CVEs?

Are there any packages in "universe" that you patch because your users would otherwise be at risk? Do you update those packages by backporting patches or by rebasing to new upstream releases?

Do you provide guidance to users about the packages they install from the Ubuntu "universe" repo collection using apt?

Do you recommend using software sources like Flatpak or Snap to give users access to application releases that are maintained and get security patches?

Is there anything else that you want users to know about your approach to vulnerability remediation or related security topics?

If this is not the best place to ask a question of the maintainers, where should I ask?

Plasma Login Manager not allowing monitors to go into power save mode

oshunluvr — Sat, 18 Jul 2026 19:16:50 GMT

Under SDDM, the monitors will go into sleep mode as expected.

Using Plasma Login Manager, the login screens stay on indefinitely.

[Post-Install]Broken disk?

nilsA — Fri, 17 Jul 2026 21:39:17 GMT

On one of tree old PCs, after a week or so, the install is broken.

It boots into:

GNU GRUB version 2.14
Minimal BASH-like line editing is supported
...
...''

grub>

When I do

I get

(hd0) (HD0,mscos|) (HD0,msdos2) (HD0, msds3) (hd0, mosdos4)

But when I do

ls (msdos0)

I get

Device hd0: No known filesystem detected - sector size 512B - Total size 488386584KiB

And the PC will not boot from CD or USB, whatever I do in the BIOS.

Is the disk bad? OR can I rescue this?

Wayland display server porblem?

joneall — Thu, 16 Jul 2026 12:09:46 GMT

I took a break for lunch and a siesta and when I got back, my screen was set on 640pixels and insisted that it was the only resolution allowed for this screen. I had to reboot to get back to normal.

In syslog, I see messages like these:

2026-07-16T12:24:34.443502+02:00 jon-desktop strawberry[2294]: 12:24:34.435 DEBUG unknown Creating a fake screen in order for Qt not to crash
...
thunderbird[3381]: [Parent 3381, Main Thread] WARNING: Couldn't map window 0x7db21075e5c0 as subsurface because its parent is not mapped.: 'glib warning',
file /build/thunderbird-VCZ2OF/thunderbird-140.12.1+build1/toolkit/xre/nsSigHandlers.cpp:201 [several hundred times]
...
2026-07-16T12:24:45.306289+02:00 jon-desktop org_kde_powerdevil: [ 9923] Emitting DDCA_Display_Status_Event[15156.935: DDCA_EVENT_DISPLAY_CONNECTED, card1-DP-1, dref: DDCA_Display_Ref[24], io_path:
/dev/i2c-9, ddc working: true]
2026-07-16T12:24:45.306402+02:00 jon-desktop org_kde_powerdevil: [ 9923] libddcutil callback thread 0x76434800f070 started
2026-07-16T12:24:45.306443+02:00 jon-desktop org_kde_powerdevil: [ 9923] Started 1 event callback thread(s)
2026-07-16T12:24:45.306734+02:00 jon-desktop org_kde_powerdevil: [ 1982] Quiescing libddcutil API...
2026-07-16T12:24:45.306795+02:00 jon-desktop org_kde_powerdevil: [ 1982] Quiesce libddcutil API complete
2026-07-16T12:24:45.306821+02:00 jon-desktop org_kde_powerdevil: [ 1982] Display redetection starting.

The AI assistant of duckduckgo tells me:

The message "Creating a fake screen in order for Qt not to crash" is related to problems with the Wayland display server in KDE environments. This occurs when Qt detects issues with the actual display, prompting it to simulate a screen to avoid crashing.

I'm at

Operating System: KDE neon User Edition
KDE Plasma Version: 6.7.2
KDE Frameworks Version: 6.28.0
Qt Version: 6.11.1
Kernel Version: 6.17.0-35-generic (64-bit)
Graphics Platform: Wayland

[System]How do you troubleshoot a freeze-up?

Shibblet — Wed, 15 Jul 2026 22:57:16 GMT

This has happened quite a few times on me now. Just a freeze-up in the middle of doing things... Mouse stopped moving, and I had no choice but to hard-boot the computer.
It's usually not a big deal, I just deal with it and move on... but now that it seems to be happening more frequently... and moreso, that I really don't even know how to begin to troubleshoot a "freeze-up."

Kubuntu 26.04: Black screen after screen lock or display power off (Wayland, NVIDIA RTX 3070)

Yamanqui — Wed, 15 Jul 2026 22:37:11 GMT

I upgraded from Kubuntu 25.10 to Kubuntu 26.04 LTS. Since the upgrade, my graphical session becomes unusable whenever the screen locks or the display powers off.

System

Kubuntu 26.04 LTS
KDE Plasma 6.6.5
Wayland session
Linux kernel 7.0.0-27-generic
NVIDIA GeForce RTX 3070
NVIDIA driver 580.159.03

Problem
The issue occurs in at least these situations:

The screen locks (loginctl lock-session)
The display powers off after inactivity
Suspend also appears to trigger the same behavior

Steps to reproduce

Log into a Plasma Wayland session.
Run:
loginctl lock-session

(or wait for the screen to lock/power off automatically.)
Attempt to wake the session.

Expected behavior
The lock screen should appear and the session should be usable after entering the password.

Actual behavior

The monitor wakes up to a black screen.
The mouse cursor is visible and can be moved.
Typing the password does not restore the session.
Ctrl+Alt+F2 (or another TTY) still works.
The system itself appears to remain running.

Additional observations
From a TTY, I tried:
systemctl --user restart plasma-kwin_wayland.service

This changed the display to what looked like the graphical login screen. The clock updated, the mouse worked, and I could type my password. However, pressing Enter caused the graphical interface to freeze completely.

From another TTY I then tried:
systemctl restart sddm

After this, the screen became black with only a white cursor/underscore in the upper-left corner, and even switching to another TTY no longer worked. I had to power-cycle the machine.

[Software]HTTP_PROXY variable for specific application - please review

boospy33 — Wed, 15 Jul 2026 17:56:41 GMT

Hello all,

I'm using SSL deep inspection through firewalls here. It works reasonably well. The only problem is when applications do things that can't be allowed by any rule, and there's no way to configure a proxy for them. For example, Steam.
So I've been experimenting with some Bash variables. My startscript:

Code:

#!/bin/bash
export http_proxy=http://fw66.tux.lan:8081
export https_proxy=http://fw66.tux.lan:8081
export HTTP_PROXY=$http_proxy
export HTTPS_PROXY=$https_proxy
export no_proxy=localhost,127.0.0.1
/usr/games/steam

And the whole thing actually seems to work very well. The firewall log confirms this, too.

My question is what do I need to watch out for to make sure that another application doesn't accidentally go through the proxy when it's not supposed to? Are there situations where this could happen?

Thanks

Can't Install Kubuntu Because it Says Ethernet is Disconnected

Breachlove — Tue, 14 Jul 2026 17:13:27 GMT

This is a fresh build with an asus x870 P-csm motherboard and a very much live wired connection right into the wall. It's the same cable and plug I used on my old PC. The installer says it's disconnected and I'm now stuck. I don't know why the OS needs a Network connection to install in the first place.

[Post-Install]Keyboard and mouse not working post installation of 26.04 (after upgrade from 25.04)

notAProgrammer — Tue, 14 Jul 2026 16:26:38 GMT

I updated from 25.04 or 25.10 to 26.04, and now my in built keyboard and mouse aren't working. They are however, working in the grub menu.In addition, the power button is correctly turning the system off.

I have two kernels - 7.0.0-27-generic - 6.17.0-40-generic. Trying to boot into the recovery mode (graphical) of the older 6.17.0-40 still leaves me with the same problem in the graphical interface. However, in recovery mode during terminal usage as root, I'm able to perform all standard I/O operations.

Any advice on what to do next?

[RESOLVED]Plasma login manager : can't change "waterfall" wall paper?

oshunluvr — Tue, 14 Jul 2026 14:02:33 GMT

Love the new plasma login manager. My dual monitors now have only a single login dialog and on the correct monitor.

However, IMO the default "waterfall" wallpaper is damn ugly. Looks like something a grade schooler would like. The configuration shows "breeze" but the selected wallpaper isn't displayed.

Has anyone figured out the trick to get a different wallpaper?

[SOLVED]An observation re. Psensor

Teunis — Mon, 13 Jul 2026 21:05:46 GMT

Hi,

Since several months or maybe even a year my laptop would suddenly loose the KDE panel and the only way to recover the system would be a hard shut down.
This would happen more and more often.

Now I found a solution, normally I'd have Psensor running but once it is off the computer regains its normal Linux stability.
To be sure and because I hardly ever looked at it anyway I uninstalled it.

no more discover

die.boer — Mon, 13 Jul 2026 17:24:07 GMT

so this is my new way off updating everything in terminal

Code:

sudo nala update && sudo nala full-upgrade && sudo snap refresh && [ -f /var/run/reboot-required ] && echo ">>> Reboot recommended <<<"

thoughts maybe ?

[SOLVED]Failure when attempting to update kernel from 7.0.0-22-generic (64-bit) to 7.0.0-27-generic

jrwatts — Sun, 12 Jul 2026 21:01:26 GMT

I'm getting an error when trying to update the kernel:

Code:

Setting up linux-image-7.0.0-27-generic (7.0.0-27.27)…
Setting up linux-headers-7.0.0-27-generic (7.0.0-27.27)…
/etc/kernel/header_postinst.d/dkms:
Sign command: /usr/bin/kmodsign
Signing key: /var/lib/shim-signed/mok/MOK.priv
Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der

Autoinstall of module hid-xpadneo/v0.9-222-gcd25680 for kernel 7.0.0-27-generic (x86_64)
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-27-generic -C '/lib/modules/7.0.0-27-generic/build' M='/var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/src' VERSION='v0.9-222-gcd25680' modules
ERROR (dkms apport): binary package for hid-xpadneo: v0.9-222-gcd25680 not found

Error! Bad return status for module build on kernel: 7.0.0-27-generic (x86_64)
Consult /var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/make.log for more information.

Autoinstall on 7.0.0-27-generic succeeded for module(s) openrazer-driver.
Autoinstall on 7.0.0-27-generic failed for module(s) hid-xpadneo(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/header_postinst.d/dkms exited with return code 1
dpkg: error processing package linux-headers-7.0.0-27-generic (--configure):
 old linux-headers-7.0.0-27-generic package postinst maintainer script subprocess failed with exit status 1
dpkg: dependency problems prevent configuration of linux-headers-generic:
 linux-headers-generic depends on linux-headers-7.0.0-27-generic; however:
  Package linux-headers-7.0.0-27-generic is not configured yet.

dpkg: error processing package linux-headers-generic (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of linux-generic:
 linux-generic depends on linux-headers-generic (= 7.0.0-27.27); however:
  Package linux-headers-generic is not configured yet.

dpkg: error processing package linux-generic (--configure):
 dependency problems - leaving unconfigured
No apport report written because the error message indicates its a followup error from a previous failure.
       No apport report written because the error message indicates its a followup error from a previous failure.
              Processing triggers for linux-image-7.0.0-27-generic (7.0.0-27.27)…
/etc/kernel/postinst.d/dkms:
Sign command: /usr/bin/kmodsign
Signing key: /var/lib/shim-signed/mok/MOK.priv
Public certificate (MOK): /var/lib/shim-signed/mok/MOK.der

Autoinstall of module hid-xpadneo/v0.9-222-gcd25680 for kernel 7.0.0-27-generic (x86_64)
Building module(s)...(bad exit status: 2)
Failed command:
make -j12 KERNELRELEASE=7.0.0-27-generic -C '/lib/modules/7.0.0-27-generic/build' M='/var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/src' VERSION='v0.9-222-gcd25680' modules
ERROR (dkms apport): binary package for hid-xpadneo: v0.9-222-gcd25680 not found

Error! Bad return status for module build on kernel: 7.0.0-27-generic (x86_64)
Consult /var/lib/dkms/hid-xpadneo/v0.9-222-gcd25680/build/make.log for more information.

Autoinstall on 7.0.0-27-generic succeeded for module(s) openrazer-driver.
Autoinstall on 7.0.0-27-generic failed for module(s) hid-xpadneo(10).

Error! One or more modules failed to install during autoinstall.
Refer to previous errors for more information.
run-parts: /etc/kernel/postinst.d/dkms exited with return code 1
dpkg: error processing package linux-image-7.0.0-27-generic (--configure):
 old linux-image-7.0.0-27-generic package postinst maintainer script subprocess failed with exit status 1
No apport report written because MaxReports is reached already
                                                              Errors were encountered while processing:
 linux-headers-7.0.0-27-generic
 linux-headers-generic
 linux-generic
 linux-image-7.0.0-27-generic
Error: Sub-process /usr/bin/dpkg returned an error code (1)

It looks like there's a problem with the `xpadneo` driver for my Xbox controller...does anyone know if this driver is still useful (I installed it years ago and it's remained through various upgrades)? I have a suspicion that I definitely don't need it when running games through Steam, but it may still be necessary for other games?