Accessibility: brightness should be adjustable from the initial boot screen

[jsfan3]

Hello,

I would like to request an accessibility improvement for Clonezilla Live.

It would be very helpful to have an easy way to adjust screen brightness from the initial boot screen, before entering the main Clonezilla environment.

For users with light sensitivity like me, visual fatigue, or low vision, screen brightness can be a real usability barrier at the earliest stage of startup.

Having this available immediately at boot would make Clonezilla more accessible and easier to use.

Thank you for considering this request.

[jsfan3]

I would also like to suggest a possible alternative: if simple brightness adjustment from the initial boot screen is not feasible, a clearly visible dark mode option in the boot menu could still help a lot.

For users with light sensitivity like me, visual fatigue, or low vision, this could make Clonezilla significantly easier to use from the very beginning of the boot process.

Thank you.

[stevenshiau]

We will add the package "brightnessctl" in the next testing Clonezilla live. You can switch to console 2 (Ctrl-Alt-F2) to do tune that.
You can use "brightnessctl info" to show the status.
To set a specific value (e.g., to 50%):
sudo brightnessctl set 50%
To increase or decrease brightness (e.g., by 10%):
sudo brightnessctl set +10%
sudo brightnessctl set 10%-

[jsfan3]

I tested clonezilla-live-3.3.2-25-amd64 (Debian testing). Unfortunately, 'brightnessctl` does not work for screen backlight control in this environment. Please see the attached photo for details.

1. brightnessctl info reports only one device: input16::compose of class leds with max brightness 1 – this appears to be a keyboard LED, not a screen backlight.
2. Trying to set a brightness percentage (e.g. sudo brightnessctl 50% or sudo brightnessctl 10%-) has no effect on the screen; it remains at max brightness.

For comparison, on the same hardware with Linux Mint 22 Cinnamon installed, I opened a text console (Ctrl+Alt+F2), and run the same brightnessctl commands: they worked correctly and adjusted the display backlight as expected. So the hardware is fully compatible with brightnessctl – the issue is specific to the Clonezilla live environment.

This makes me suspect that the live system may be missing a required kernel module for backlight control, or perhaps a necessary udev rule is not in place.

If possible, could you try brightnessctl on your real machine with the current Clonezilla live, to see if the backlight device is detected there?

One more usability note: Ctrl+Alt+F2 to switch to a text console is only available after the keyboard layout configuration step and once Clonezilla’s main interface has started.

[jsfan3]

Ia the brightness-udev package included in Clonezilla Live?

[stevenshiau]

Package brightness-udev is not included in Clonezilla live.
We can add that in the next release.
Could you please install that in the live system (sudo apt update; sudo apt install brightness-udev) and test it again on your machine?
Thanks.

[jsfan3]

Ok, I used ocs-live-netcfg to get Internet access.

Installing brightness-udev has no effect on Clonezilla Live Testing based on Debian.

Conversely, installing brightness-udev on Clonezilla Live Testing based on Ubuntu 26.04 LTS "Resolute Raccoon" produces an error because updating the initramfs is required. Ubuntu's behavior seems the most sensible to me. It makes sense that installing brightness-udev requires a reboot. Therefore, it is not feasible for me to install brightness-udev in a live environment.

Only you can add it to the next testing release. By the way, when will it be released?

I'm attaching a photo:

[stevenshiau]

Please give testing Clonezilla live >= 3.3.2-26 or 20260502-* a try:
https://clonezilla.org/downloads.php
The package brightness-udev is now included in the live system.
Please let us know the results. Thanks.

[jsfan3]

Thank you for your prompt response.

I tried: clonezilla-live-20260502-resolute-amd64.zip

It doesn't boot. A few seconds after selecting the second menu item, "800x600 VGA & To Ram", a kernel panic occurs, as shown in the photos below.

[stevenshiau]

How about clonezilla live 3.3.2-26 or 20260502-questing?

[jsfan3]

clonezilla-live-20260502-questing-amd64.zip boots without a kernel panic. However, nothing has changed with brightnessctl; it only detects the LEDs (keyboard backlight and others) but not the monitor. Maybe it requires Nvidia drivers loaded into the kernel, since I have an Nvidia card? This is getting complicated...

Regarding the kernel panic, would you like me to report it in a separate issue on GitHub?

[stevenshiau]

Try to enter the KMS mode in this boot menu:
https://clonezilla.org//fine-print-live-doc.php?path=./clonezilla-live/doc/01_Save_disk_image/01-clonezilla-boot-menu.doc#01-clonezilla-boot-menu.doc
Then some of the kernel modules will be loaded, and it might support your hardware better, especially those related to VGA output.
In my best case, "brightnessctl -l" shows the "intel_backlight" in KMS mode, while in the normal boot menu it does not since some of the modules are in the blacklists and it might block your backlight module I believe.