Dracut v055-r4 does not support kernel module compression, it has no USE flag to enable it. See also https://forums.gentoo.org/viewtopic-t-1112566-highlight-dracut.html
Please describe the problem you are experiencing, and provide steps to reproduce it.
I suspect you didn't enabled nessessary USE flags for sys-apps/kmod
I have enabled relevant USE flags (zstd). This is ouput from 'equery uses kmod' [ Legend : U - final flag setting for installation] [ : I - package is installed with flag ] [ Colors : set, unset ] * Found these USE flags for sys-apps/kmod-29: U I - - debug : Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces - - doc : Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally + + lzma : Enable support for XZ compressed modules - - pkcs7 : Enable PKCS#7 signature parsing for modinfo. - - python : Add optional support/bindings for the Python language - - python_targets_python3_10 : Build with Python 3.10 - - python_targets_python3_8 : Build with Python 3.8 + + python_targets_python3_9 : Build with Python 3.9 - - static-libs : Build static versions of dynamic libraries as well + + zlib : Enable support for gzipped modules + + zstd : Enable support for ZSTD compression Steps to reproduce. 1. Compile vanilla-sources with Arch config (enables module compression with zstd) 2. Run dracut. Dracut will report errors like 'dracut-install: Failed to find module 'dm_delay' /lib/modules/5.17.3//kernel/drivers/md/dm-delay.ko.zst' for each kernel module. Running dracut with '--verbose' flag shows that it did not include any kernel module (image folder /lib/modules/ only contains dummy files like ''module.symver' etc). When I initially posted message at gentoo forum at May 2020 Arch was using xz compression and I enabled 'lzma' USE flag - result was the same. So, it seems that something blocks using compressed modules by dracut and this is not kmod.
P.S. I have noticed the double slash at '5.17.3//kernel' and appended dracut parameter '-k /lib/modules/5.17.3' (without ending slash) to fix this - it didn't yield anything. I also rechecked several times that listed in dracut output kernel modules are present. There is interesting thread: https://github.com/dracutdevs/dracut/issues/945. According to it dracut received zstd support in 2021 in version 28, so it should work. However it does not work in my setup and in May 2020 the xz compression didn't work either, so this problem is not specific to zstd. In October 2021 in that thread one user reported that '-o busybox' dracut option can be used as a fix (because 'its modprobe overwrites kmod's, and doesn't support zst modules'), but it didn't worked for me.
P.P.S Removing compression in kernel config file resolves the issue, but it is obviously not a solution. This shows that the problem is not in some obscure (unrelated to compression) kernel config option which causes the problem.
dracut-install uses libkmod to search modules, so this doesn't look like a dracut issue right now. Could you check if modules can be loaded with 'modprobe' command?
I cannot check because this is initial install and I cannot create initramfs which is needed to boot.
Is "modinfo dm_delay" able to find the compressed module file? That should tell us if the libkmod functions are working.
For reference: Support for modules compressed with zstd was added in dracut-054. https://github.com/dracutdevs/dracut/commit/ce9af251af5fca08ea206ef980005853a4dac36e
(In reply to Mike Gilbert from comment #8) This is the correct command, since this is initial install and running kernel is different: modinfo -k 5.17.3 dm_delay
I was able to create an initramfs using dracut containing modules compressed using zstd without any issues. To test, I created the config snippet below: > % cat /etc/kernel/config.d/zstd.config > CONFIG_MODULE_COMPRESS_ZSTD=y I then installed sys-kernel/vanilla-kernel-5.15.34. Many .ko.zst files were installed in /lib/modules/5.15.34-dist. > % find /lib/modules/5.15.34-dist -name '*.ko.zst' | wc -l > 3945 I then generated an initramfs using dracut: > % sudo dracut --kver 5.15.34-dist /tmp/foo.img This completed without any errors. Running lsinitrd on the resulting file shows many .ko.zst files. > % sudo lsinitrd /tmp/foo.img | grep -F '.ko.zst' | wc -l > 947
