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Question about #ubuntu #linux #kernel...

My updated ubuntu 26.04.01 is still using a 6.17 OEM kernel:

$ uname -r

6.17.0-1032-oem


But it looks like a newer 7.0 kernel has been installed:

$ dpkg --list | grep linux-image | grep "^ii"

ii linux-image-6.17.0-1032-oem 6.17.0-1032.32 amd64 Signed kernel image oem
ii linux-image-7.0.0-38-generic 7.0.0-38.38 amd64 Signed kernel image generic
ii linux-image-generic 7.0.0-38.38 amd64 Generic Linux kernel image
ii linux-image-generic-hwe-26.04 7.0.0-38.38 amd64 Generic Linux kernel image


Should I update to use the 7.0 kernel? How do I do that?

@Khurram Wadee - you let us know when updating your kernel. Any advice for a luddite?

#linux #ubuntu #kernel @Khurram Wadee

N. E. Felibata II reshared this.

Khurram Wadee
Khurram Wadee  
•
I think Ubuntu uses apt for updating software and so you could try
$ sudo apt upgrade
but I'm not sure how often the kernel is updated and it might not match the version above. You could try a manual installation. I found this link which might be of use: https://linuxvox.com/blog/updating-linux-kernel-ubuntu/

Updating the Linux Kernel in Ubuntu: A Comprehensive Guide

The Linux kernel is the core of the Linux operating system, managing system resources, hardware interactions, and providing a stable environment for applications to run. In Ubuntu, keeping the kernel up-to-date is crucial for several reasons.
linuxvox
juliadream
juliadream  
•
you have to turn off the "secure boot" crap to run a newer kernel than the shipped default.. go have a read of https://github.com/bkw777/mainline?ref=itsfoss.com

GitHub - bkw777/mainline at itsfoss.com

Install mainline kernel packages from kernel.ubuntu.com - bkw777/mainline
GitHub
Noam נעם
Noam נעם  
•
Thanks both. I've been looking at the blog Khurram mentioned. If I understand correctly, the system is running the old kernel even though a newer one is installed. Julia, I'm afraid I can't follow the github page. I don't know what I'm looking at.
Andrew Pam
Andrew Pam  
•
You have already installed multiple kernels; you just need to pick the one you want during boot, or set the default for the next boot. How to do that depends on what boot loader you're using.
Noam נעם
Noam נעם  
•
Thanks Andrew. I'll look that up tomorrow. And back stuff up before I try.
Andrew Pam
Andrew Pam  
•
It's always good to have backups, but what you're doing here is pretty safe - the system should run with either kernel, and you should be able to switch between them whenever you boot. So the fallback if something goes wrong is normally just "reboot and pick the known working kernel". Which is why you will normally have more than one installed as a result of regular updates.
Noam נעם
Noam נעם  
•

OK, complete failure in trying to boot the laptop using a different kernel. I've looked through these two write-ups:

How to List and Switch Between Installed Kernels on Ubuntu
https://oneuptime.com/blog/post/2026-03-02-how-to-list-and-switch-between-installed-kernels-on-ubuntu/view

Updating the Kernel in Ubuntu: A Comprehensive Guide
https://linuxvox.com/blog/update-kernel-ubuntu/#checking-your-current-kernel-version

I know that a 7.0.0 kernel exists on the laptop, I don't know how to reboot using it. Any advice appreciated.


How to List and Switch Between Installed Kernels on Ubuntu

Learn how to list installed kernels on Ubuntu, check which kernel is running, switch between kernel versions, and manage kernel installations for testing and rollback purposes.
Nawaz Dhandala (OneUptime)
Andrew Pam
Andrew Pam  
•
What bootloader are you using? Grub? Does it delay during boot and ask you to choose? If not, you may need to hold "Shift" or press "Esc" repeatedly during boot to bring up the menu.
Noam נעם
Noam נעם  
•

Erm... I assume Grub? There is a /boot/grub/ directory

I can get to a detailed booting menu by pressing 'Enter', but holding 'Shift' does nothing. But I didn't see anything there relating to kernels.

Andrew Pam
Andrew Pam  
•
What options does the menu present?
Noam נעם
Noam נעם  
•
Don't remember... I'll have to reboot and look.
Noam נעם
Noam נעם  
•

It's something like:

F1 BIOS setup
F5 ASSET info
F9 Regulatory info
F10 diagnose hardware
F12 Temp startup device

I've browsed without changing anything, and not found anything listing a kernel or similar to the kernel number.

Andrew Pam
Andrew Pam  
•
Ah, that's not the grub menu; that's your BIOS boot menu, which is at an earlier stage. You need to let the boot continue beyond that point. It may be easier to change your grub settings to enable the boot menu timeout rather than just proceeding immediately to the default kernel. Edit the GRUB_TIMEOUT line in /etc/default/grub with your chosen delay in seconds and then run "sudo update-grub". The next reboot should wait that long for you to interrupt the default boot and make a different selection.
Andrew Pam
Andrew Pam  
•
If you're not on a Debian-based distribution, the grub update command will be different.
Noam נעם
Noam נעם  
•
OK, thanks. Let me write this down with pen and paper so I can fiddle and reboot. I'm on Ubuntu, I assume that'll be the same commands.
Noam נעם
Noam נעם  
•
Maybe I should look at diaspora on my phone while doing this. 💡
Khurram Wadee
Khurram Wadee  
•
On Fedora, if you hold down F8 on boot, the Grub menu comes up.
Noam נעם
Noam נעם  
•

Hooray! I got to a screen that says:

grub>

Andrew Pam
Andrew Pam  
•
Yes, Ubuntu is based on Debian, so those are the correct commands. If you just get the grub> prompt but not a list of kernels, that usually means that it couldn't find the grub.cfg configuration file or that you chose to go to the grub command line rather than picking from the menu. You should be able to type "boot" at that prompt and get back to the OS if the config file is available.
Noam נעם
Noam נעם  
•

Guessing I need something like

linux /vmlinuz ...

?

Noam נעם
Noam נעם  
•

Whoops. "boot" gives me:

you need to load the kernel first

Andrew Pam
Andrew Pam  
•
It may be easier to just reboot again (ctrl-alt-del) and let it start normally.
Noam נעם
Noam נעם  
•
Well, "exit" resumed normal booting. So I haven't managed to choose a different kernel, but I haven't broken the laptop either.
Andrew Pam
Andrew Pam  
•
OK, now set the timeout and do the update-grub; also check that GRUB_TIMEOUT_STYLE in /etc/default/grub is "menu" or "countdown" not "hidden". If it's "hidden", you need to hold shift during the timeout period.
Noam נעם
Noam נעם  
•

Thanks, I've down the Timeout already. It does say "hidden", and I held shift to get to the grub prompt.

One of the pages listed above has a section "Temporarily Booting a Different Kernel" and I'm trying to follow it. I did this bit:

List available GRUB entries with their numbers


awk -F\' '/^menuentry |^submenu / {print i++, $2}' /boot/grub/grub.cfg

And I get
0 Ubuntu
1 Advanced options for Ubuntu

So I think that to choose a different kernel, I need something like:
sudo grub-reboot "1>2"

But I don't know what the submenu looks like, so "1>???"

Noam נעם
Noam נעם  
•
(sorry for extra large font, not sure how that happened)
Andrew Pam
Andrew Pam  
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Change “hidden” to “menu” or “countdown”, run the “sudo update-grub”, reboot, get to the menu, choose “Advanced” to see the submenu which should include a choice of kernels.
Andrew Pam
Andrew Pam  
•
You can indeed set it from the command line using "grub-reboot", but that's doing it the hard way. 😀 The options including what all the submenu items are can all be found in the grub config file, usually at /boot/grub/grub.cfg
Noam נעם
Noam נעם  
•
Thanks, I'll try another reboot...
Andrew Pam
Andrew Pam  
•
That awk command was just printing the top-level entries (because of the “^” caret anchoring the selection to the start of the line; submenu items are “menuentry” but indented and so don’t match unless you remove the caret). Or you could just read through the file, for example with “less”.
Noam נעם
Noam נעם  
•

Hooray!

$ uname -r
7.0.0-38-generic

Thank you so much @Andrew Pam. 🥰
I'll try using the laptop with this kernel and see if all is well. Then I'll try to figure out how to make it the default.

@Andrew Pam
Noam נעם
Noam נעם  
•
Note to self: Make a text file with that I've learned here, or I'll forget it by tomorrow.
Andrew Pam
Andrew Pam  
•
The "#" character in the shell is a comment; in Markdown, which is used for Diaspora posts and comments, it's a heading. A single # is therefore a top-level H1 heading. If you don't want that, you need to use the "<>" (insert code) around your section, like this:
# comment
command
Andrew Pam
Andrew Pam  
•
And remember that you can preview comments!
Andrew Pam
Andrew Pam  
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If you set "GRUB_DEFAULT=saved" and "GRUB_SAVEDEFAULT=true" it will save whichever kernel you pick, then keep using that until you pick a new one. As usual, you'll need to sudo update-grub after making changes.
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