[SOLVED] No kernel information in LMDE Update Manager

[br1anstorm]

I have Mint 19.x on my regular daily-use computer. I have installed LMDE4 on a second, "spare" laptop.

I have just updated the latter (including the latest version of its kernel). I noticed that (unlike Mint 19.x) the LMDE Update Manager does not have, under the "View" tab, an option to see the list of current and previous kernels.

Is there a reason for this omission? I find that list very useful in Mint 19.x, as it enables me to check and selectively prune/delete old kernels.

I'd like to do the same in LMDE4. If I can't review and delete old kernels via the Update Manager, how can I do so?

EDIT: As has been my habit, I looked at Pjotr's useful website of tips when posting this query. But even his advice on removing old kernels refers only to the ways of doing so via the Update Manager. And LMDE seems not to offer this route.

[axisofevil]

The contents of /boot (under several different guises) will tell you what kernels you have.
Or you could choose "advanced options" at boot time to be shown a list.
I tend to use synaptic to remove old kernels.

For example, I have 3 kernels :- 4.19, + two 5.10 backports.

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ls -l /boot
-rw-r--r-- 1 root root   206194 Apr 27  2020 config-4.19.0-8-amd64
-rw-r--r-- 1 root root   236170 Jun  4 07:23 config-5.10.0-0.bpo.7-amd64
-rw-r--r-- 1 root root   236202 Aug  7 07:00 config-5.10.0-0.bpo.8-amd64
drwxr-xr-x 3 root root     4096 Jan  1  1970 efi
drwxr-xr-x 6 root root     4096 Oct 14 20:49 grub
-rw-r--r-- 1 root root 56243952 Apr 13  2021 initrd.img-4.19.0-8-amd64
-rw-r--r-- 1 root root 71477427 Jul 20 14:20 initrd.img-5.10.0-0.bpo.7-amd64
-rw-r--r-- 1 root root 71485946 Sep  9 21:29 initrd.img-5.10.0-0.bpo.8-amd64
-rw-r--r-- 1 root root  3408461 Apr 27  2020 System.map-4.19.0-8-amd64
-rw-r--r-- 1 root root       83 Jun  4 07:23 System.map-5.10.0-0.bpo.7-amd64
-rw-r--r-- 1 root root       83 Aug  7 07:00 System.map-5.10.0-0.bpo.8-amd64
-rw-r--r-- 1 root root  5274864 Apr 27  2020 vmlinuz-4.19.0-8-amd64
-rw-r--r-- 1 root root  6807296 Jun  4 07:23 vmlinuz-5.10.0-0.bpo.7-amd64
-rw-r--r-- 1 root root  6808800 Aug  7 07:00 vmlinuz-5.10.0-0.bpo.8-amd64

[Aztaroth]

I noticed that (unlike Mint 19.x) the LMDE Update Manager does not have, under the "View" tab, an option to see the list of current and previous kernels.

You're right. In LMDE4, you have to manage your kernels with commands in Terminal. Here are the basics :

List of installed kernels and their status (installed or deinstalled) :

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dpkg --get-selections|grep linux-image

example from my PC :
linux-image-4.19.0-17-amd64 deinstall
linux-image-4.19.0-18-amd64 install
linux-image-4.19.0-8-amd64 deinstall
linux-image-5.10.0-0.bpo.8-rt-amd64-unsigned install

List of official available kernels for Debian 10 (which is LMDE4's base) :

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apt search linux-image

Long list by the way, can be shortened for a specific version :

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apt search linux-image-5.10

will only search for 5.10 kernels

Uninstall a kernel (VERSION needs to be the exact match of the kernel's name, eventually use first command to get it) :

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sudo apt remove linux-image-VERSION

example : sudo apt remove linux-image-4.19.0-17-amd64

Install a kernel (VERSION needs to be the exact match of the kernel's name, eventually use second/third command to get it) :

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sudo apt-get install linux-image-VERSION

example : sudo apt-get install linux-image-5.10.0-0.bpo.8-rt-amd64-unsigned (last kernel for standard PC)
(you don't have to upgrade grub, it's done automatically at the end of the process, just reboot to have your new kernel working)

You may notice I used apt for uninstall and apt-get for install. It was just to underline that both commands can be used. I use apt-get because it's the lower level command (means apt uses apt-get), but both work.

[Aztaroth]

I'll add two remarks to my previous post :
- an obvious one : take a snap with Timeshift before upgrading your kernel.

- about graphics drivers : I don't use proprietary drivers because nouveau module works fine.
If you really need proprietary drivers, upgrade kernel first, then graphic driver. At least with Nvidia (don't know for AMD), the driver binds with the kernel and further kernel upgrades may cause troubleshooting.
Here for more info :
https://wiki.debian.org/DontBreakDebian ... ll_scripts

[br1anstorm]

Well, many thanks to both @Aztaroth and @axisofevil for those helpful replies.

First things first (picking up a point in the last post above from @Aztaroth).... I do indeed always take a system snapshot in Timeshift before every kernel upgrade. But it's sensible to have this reminder.

Thankfully, I have not had any problems over graphics drivers on either my Mint 19.x or my LMDE4 computers (neither has an Nvidia graphics card) - so I'm using the default driver(s).

I was of course aware that the Advanced options in Grub lists the various kernels available. I just didn't know how to remove any of them!

I haven't gone hunting for alternative kernels or backported options. In my LMDE4 system I have just taken each kernel-update when it's offered in the Update Manager. I've just checked: I have

linux-image-4.19.0-16-amd64 install
linux-image-4.19.0-17-amd64 install
linux-image-4.19.0-18-amd64 install
linux-image-4.19.0-8-amd64 install
linux-image-amd64 install

I admit to being a little mystified by the last of these....

As for selectively uninstalling older kernels, I hadn't explored how to do so using Synaptic. The terminal commands suggested by @Aztaroth seem fairly clear and straightforward, so I may try that route.

But I can't help observing that the method offered in Mint 19.x using the Update Manager is a whole lot simpler and - probably - less vulnerable to error. Surely it would be a good idea for the developers of LMDE to adopt this and add the 'kernel info' option into the Update Manager? Or is it more complicated than that?

[Aztaroth]

But I can't help observing that the method offered in Mint 19.x using the Update Manager is a whole lot simpler and - probably - less vulnerable to error. Surely it would be a good idea for the developers of LMDE to adopt this and add the 'kernel info' option into the Update Manager? Or is it more complicated than that?

Mint and LMDE4 don't use the same version of kernels : LM uses Ubuntu based kernels and LMDE4 Debian based kernels.
Also, but that's a personal opinion, is an easy kernel change a plus or a minus ?
If you run across the topics, you'll find a lot of "XXX Problem or Black screen after kernel update". This almost never happens with LMDE4 because the kernel upgrade is not so easy to perform, not really necessary too (LMDE4 can spend all its life with the native kernel if it's run correctly after first boot) and needs to put the hands under the hood, so that, at least, you will understand what's going on and not rely on hoping all the best after a click.
Of course, for non-critical upgrades, a Manager is a great plus. For kernels, I'm not sure, because lots of things can go wrong after an update. But I may also be proven wrong, one obvious reason being that I'm sure the LM Team does advanced tests before releasing a new kernel.

[br1anstorm]

That's useful and interesting comment. I am certainly at the "conservative" end of the user spectrum and I value reliability. I approach kernel updates with caution precisely because I've observed that people run into problems when they do so.

I think I was careless in referring in an earlier post to kernel upgrades. I should have said updates - because I have always been focused on updating to the latest version of the kernel within the same series - in this case 4.19.0-x. I would not dare to try to shift to - say - a 5.10.0 kernel just because it might be newer.

I seem to recall that when I first moved over to Linux with Mint 13.x, the Update Manager back then did not automatically recommend updates - even to the same kernel. You had to opt for the "higher risk" setting in order to apply kernel updates.

Nowadays I still tend to rely on what the Update Manager recommends. So I will usually install a newer version in the same kernel-series if one is listed. But I don't think I have ever added, or changed to, a different kernel in any installation.

My only reason for looking to delete older versions of the [same] kernel is simply a "housekeeping" strategy, to keep the system tidy, free up space, and get rid of stuff that is no longer required or useful. But precisely because of the potential to get it wrong and remove something I shouldn't, when it came to kernel updates I was comfortable relying on the Update Manager list with its "remove" option. But with LMDE, if terminal commands are what works, then I'll just have to get used to that!

Anyway, the explanations and guidance kindly provided means that I can mark this thread "Solved" - so thanks again....