Linux Mint has announced an overhaul in its kernel management, and will now automatically delete old kernels once a week.
Kernel management is moving out of Update Manager and into the System Administration tool on both standard and LMDE versions and it will now tracks kernels by series rather than individual versions.
You’ll get to choose which kernel series’ are tracked and how many older kernels within each series the system should keep (in addition to the one you’re booted on; it doesn’t yank out the rug under its own feet).
Updates for tracked series’ kernels continue to appear in Update Manager as before but in a marked change, older, unused kernel versions will be removed once a week. A History button will let you easily see which kernels were removed and when.
A manual ‘Clean up’ button has also been added to let you ‘free up space immediately’, says Mint project leader Clement Lefebvre.
Individual kernels can be marked as ‘Protected’, which exempts from cleanup irrespective of your other settings or conditions. Plainly: to prevent a specific kernel from being deleted, regardless of whether it’s tracked, always mark it as protected via the ‘View all kernels’ dialog.
Installing a kernel from another series, e.g., OEM, Azure, IBM, Real Time, will prompt the tool to list the full series and provide you the option of tracking it. Tracking automatically installs any related meta-packages and future updates, so is worth doing.
While custom kernels you might install – from a random PPA or a .debs for example – can’t be “tracked”, you can mark them as tracked to prevent them being removed by the clean up processes. However, Linux Mint’s tool will warn you that it’s your responsibility to update them.
If you don’t pay much attention to updates you might not be aware of how many kernel updates are released and installed – and stay installed side-by-side. Select the ‘additional options’ for a distro in the GRUB boot loader to see a list of all those installed and bootable.
Old kernels take up space and if they’re never used or needed – the active one works fine – keeping them around isn’t vital. It is generally advised to keep one known backup kernel around, though.
It’s not clear from Mint’s blog post if these changes will come to existing Linux Mint 22.3 and LMDE as a software update, or if it’s a scheduled change coming in Linux Mint 23 ‘Alfa’ (codename temporary), which is due for release at the end of the year.