Ubuntu
dkms package

Removing dkms-built modules for old kernel versions

Asked by Ralph Corderoy on 2012-01-23

I'm aware that as new kernels are installed on `apt-get dist-upgrade'
old ones aren't removed and must be done manually, e.g.

    sudo apt-get purge linux-image-2.6.35-{22,27,28,30}-generic \
        linux-headers-2.6.35-{22,27,28,30} \
        linux-headers-2.6.35-{22,27,28,30}-generic

However, this doesn't clean up modules that dkms has built for those
kernels.

    $ dkms status
    nvidia-current, 260.19.06, 2.6.35-31-generic, x86_64: installed
    nvidia-current, 260.19.06, 2.6.35-32-generic, x86_64: installed
    nvidia-current, 260.19.06, 2.6.35-30-generic, x86_64: built
    nvidia-current, 260.19.06, 2.6.35-28-generic, x86_64: built
    nvidia-current, 260.19.06, 2.6.35-27-generic, x86_64: built
    nvidia-current, 260.19.06, 2.6.35-22-generic, x86_64: built
    $

What's the right, clean, complete way to purge these too? Is it

sudo dkms remove -m nvidia-current -v 260.19.06 \
$(printf -- '-k %s\n' 2.6.35-{22,27,28,30}-generic)

Aside: Is there anything else that may linger for each old kernel that
needs manual clean-up? I didn't find much suggesting the `dkms remove'
was needed amongst the `remove your old kernel' blog posts and HOWTOs so
perhaps there are other non-dkms things you happen to know of.

Also, it seems a shame there's not a package one can install and
configure to keep the last N kernels and purge older ones as new ones
are installed. Then only it would need to know of all the things that
need doing.

Question information

Language:: English Edit question

Status:: Solved

For:: Ubuntu dkms Edit question

Assignee:: No assignee Edit question

Solved by:: Ralph Corderoy

Solved:: 2012-01-29

Last query:: 2012-01-29

Last reply:: 2012-01-28

Link existing bug

Revision history for this message

Sam_ (and-sam) said on 2012-01-23:

Afaik, Oneiric and Precise dkms modules are removed when purging a kernel image. Will post the exact wording from Precise.

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Sam_ (and-sam) said on 2012-01-23:

Removal of linux-image-3.2.0-7-generic ...
Examining /etc/kernel/prerm.d.
run-parts: executing /etc/kernel/prerm.d/dkms 3.2.0-7-generic /boot/vmlinuz-3.2.0-7-generic
dkms: removing: bcmwl 5.100.82.38+bdcom (3.2.0-7-generic) (x86_64)

-------- Uninstall Beginning --------
Module: bcmwl
Version: 5.100.82.38+bdcom
Kernel: 3.2.0-7-generic (x86_64)
-------------------------------------

Status: Before uninstall, this module version was ACTIVE on this kernel.

wl.ko:
- Uninstallation
   - Deleting from: /lib/modules/3.2.0-7-generic/updates/dkms/
- Original module
   - No original module was found for this module on this kernel.
   - Use the dkms install command to reinstall any previous module version.

depmod.........

DKMS: uninstall completed.

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Ralph Corderoy (ralph-inputplus) said on 2012-01-24:

Thanks Sam_, good news on it happening as part of kernel removal in
later releases. I'm on 10.10 so it doesn't. So is my proposed

sudo dkms remove -m nvidia-current -v 260.19.06 \
$(printf -- '-k %s\n' 2.6.35-{22,27,28,30}-generic)

the right thing?

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Sam_ (and-sam) said on 2012-01-25:

Not sure about nvidia since I don't use it, isn't it in /lib/modules/ somewhere?

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Ralph Corderoy (ralph-inputplus) said on 2012-01-28:

Well, /var/lib/dkms/nvidia-current too and possibly elsewhere, that's why I'm after the correct dkms incantation to avoid messing things up and only finding out when nvidia is upgraded in the future.

Revision history for this message

Sam_ (and-sam) said on 2012-01-28:

When a kernel-image is removed there shouldn't be an issue by removing the regarding module when the next kernel brings it's own module again.
Looking at manpage the dkms_rm cmd looks rather simple and saying in case it'll error out.

Rather unsure though how the /etc/kernel/prerm.d cooperates with manual remove in earlier kernel-images regarding interference of upgrades. Maybe try websearch or ask on #ubuntu-kernel.

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Ralph Corderoy (ralph-inputplus) said on 2012-01-29:

I asked on #ubuntu-kernel but no reply.

I've run my proposed `sudo dkms remove' given above when I opened this question and it seems to have worked fine. The old files have been removed. However, each depmod reported

Status: This module version was INACTIVE for this kernel.
depmod....(bad exit status: 1)

We'll see if everything pans out OK on the next kernel upgrade. I expect so, it would just be nice to know for certain it's the correct way rather than suck it and see. :-)

Revision history for this message

Sam_ (and-sam) said on 2012-01-29:

If it says: was INACTIVE for *this* kernel, maybe depmod is complaining about 'inactive' or rather it couldn't examine the already purged kernel.
Anyway an exit status '1' doesn't implicate something dramatically. A websearch on 'bad exit 1' reveals some posts where user rather compiled their own kernel, e.g. bug 292606, instead of running it on stock kernel.
Maybe:
sudo depmod -a
gives a hint?
http://manpages.ubuntu.com/manpages/oneiric/en/man8/depmod.8.html