Hi, On Fri, Dec 19, 2025 at 01:47:12PM +0100, Nicolas Kovacs wrote: > Is is possible to downgrade Debian Trixie's default 6.12 kernel to an older > LTS kernel like the 6.6, the 6.1 or the 5.15 ? And if so, what would be an > orthodox way to do that ?
I see you have solved your issue but I wanted to say that while it is possible to use a Debian package of older kernel version, it isn't supported by Debian so you risk it not working and you would be missing security patches. The kernel package that comes with the updates for the current stable release is what you are expected to use. If you downloaded an older deb package from the stable release, or even one from an earlier release, it's likely that installing it with: # dpkg -i yourfile.deb or # apt install ./yourfile.deb is going to work and probably boots okay, but not necessarily. As it's not supported there's no one that can/will help you with that. Other things that don't come with official support but are probably better: - Installing a trixie-backports kernel package - Installing a kernel package from testing, sid or experimental Those choices would at least get updated to fix security issues, though possibly not at the same kind of speed that stable gets the fixes. If the problem you're trying to avoid has been fixed upstream then you can follow the instructions in the Debian kernel handbook to build your own kernel package from an upstream source release. Again here there would be some question over compatibility — for example if upstream changes or introduces some feature that Debian stable can't deal with, things might be a little strange — but as such source releases are supported by upstream you could at least keep building new packages to remain current. Those are the sorts of things I can and have done to get around some issue, rather than just reverting to an older package and sticking here. Thanks, Andy -- https://bitfolk.com/ -- No-nonsense VPS hosting
