eclean-kernel is a small tool aimed at removing old and stale kernel files. It does not only remove old kernels itself but also tries to remove all related files including auxiliary files in /boot, kernel modules and even the source tree.
The typical use is:
eclean-kernel -n 3 -p
-n 3 is used to keep three newest kernels around, and
eclean-kernel only print kernels which would be removed.
In case the results are satisfactory, use:
eclean-kernel -n 3
to actually remove the kernels.
If you are unsure whether kernel files are mapped correctly, you can use list mode:
which just lists found kernels with file mappings.
Some default options can be specified in
eclean-kernel.rc file in a location
mandated by the XDG configuration directory setting, e.g.
The file format is very simple -- additional command-line options are specified
in shell style. For example, to keep three newest kernels and always preserve
~/.config/eclean-kernel.rc would contain:
-n 3 -x config
The options read from config files will be parsed before actual command-line options, so the latter will override them.
Fiding and mapping kernels
eclean-kernel supports two distinct /boot layouts: the bootloader spec
layout (gummiboot / systemd-boot) and the legacy /boot layout.
The former is used if
are found, otherwise the latter is used.
The bootloader spec layout uses subdirectories of
named after kernel versions. It expects the kernel to be named
linux, and initramfs to be named
initrd. However, it collects
arbitrary files in that directory as well.
The legacy layout scans all files directly in
that are named as
PREFIX-VERSION. Files recognized as bzImages
can have any prefix, other files use a predefined list of prefixes.
In both layouts, eclean-kernel looks for kernel modules
/lib/modules/REALVERSION where REALVERSION corresponds to
the actual kernel version string used by the kernel itself. It is read
from kernel image and it is assumed to be equal to VERSION for libdirs
unmatched to any kernel image.
In other words, genkernel-generated
Choosing kernels to remove
The kernel choice algorithm is quite simple:
- If the kernel is currently used, don't remove it;
- If the kernel is referenced by a bootloader, don't remove it
- If auxiliary files do not map to existing kernel, remove them;
--allis used, remove the kernel;
- If kernel is not within N newest kernels (where N is the argument
-n), remove it.
The program always derefences symlinks and counts real path references. Thus, a particular file will be removed only if all kernels referencing it are removed as well. This is especially important for shared kernel sources.
In order to determine kernels currently used, eclean-kernel is supposed to read configuration files used by the bootloader. Right now, the following bootloaders are supported (and looked up in the following order):
There is also a pseudo-bootloader module called symlinks which assumes files
/boot/PREFIX.old are used.
By default, eclean-kernel uses the first bootloader from the above list for
which a configuration file exists, and uses symlinks as a fallback. This can
be changed using
eclean-kernel -l ls -l /boot /lib/modules/*
If relevant, please attach bootloader configuration files as well.