Upgrading to =app-emulation/lxc-4.0.9-r1 broke existing containers startup. It also prevented new containers to be created, they would also fail to start. Detailed logs will be attached, but in short the failure is: 'conf.c:lxc_setup_rootfs_prepare_root:3452 - Failed to setup rootfs for' This has been observed to fail with amd64 gentoo and debian containers. Without any other changes, just going back to the previous version: app-emulation/lxc-4.0.6 allows the containers to start again. This seems like a regression. Gentoo kernel: 5.12.9 on amd64 arch Reproducible: Always Steps to Reproduce: 1. Compile app-emulation/lxc-4.0.9-r1 2. Try to start existing container with: lxc-start -n <container name> or try to create a new one and then start with: lxc-create -t download -n test -- -d debian -r bullseye -a amd64 --keyserver hkp://p80.pool.sks-keyservers.net:80 Actual Results: Containers fail to start Expected Results: Containers start successfully
Created attachment 715002 [details] lxc start log, debian container
Created attachment 715005 [details] lxc start log, gentoo container
Well it seems to work for me... Are you perhaps using openrc, and if you are, what are your rc_cgroup_mode, rc_cgroup_controllers (or rc_controller_cgroups) and related rc_cgroup_settings? Some recent openrc update seems to have broken cgroups mode.
Hello Sam, This is openRC init system, indeed. There have been no modification on those settings in rc.conf, so the system uses the package default settings: $ grep -e "rc_cgroup_mode\|rc_cgroup_controllers\|rc_controller_cgroups\|rc_cgroup_settings" /etc/rc.conf #rc_cgroup_mode="hybrid" #rc_cgroup_controllers="" #rc_cgroup_settings=" #rc_cgroup_settings="" #rc_controller_cgroups="YES"
and the version of openrc is: =sys-apps/openrc-0.42.1-r1
From 'strace -f': [pid 7509] openat2(24, ".lxc_keep", {flags=O_RDONLY|O_CREAT|O_NOCTTY|O_NOFOLLOW|O_CLOEXEC, mode=0600, resolve=RESOLVE_NO_XDEV|RESOLVE_NO_MAGICLINKS|RESOLVE_NO_SYMLINKS|RESOLVE_BENEATH}, 24) = 25 I could identify that it has 'RESOLVE_NO_SYMLINKS', and my /var/lib/lxc directory is a symlink to the containers directory on a different filesystem. Replacing the symlink with a bind mount resolved the problem and now the containers startup with =app-emulation/lxc-4.0.9-r1. This can be closed now. Thanks for looking into it.
Thanks for explaining the solution, I should still look into openrc-cgroups issues but it's definitely something outside my area of expertise.
Hi! I ran into the same problem and I believe I found the proper solution! You need to have /etc/lxc/lxc.conf ( lxc.system.conf (5) ) with the setting: lxc.lxcpath = <your lxc root> ^ This will make lxc find the containers in other directory than /var/lib/lxc And need also container configs ( lxc.container.conf (5) ) specify: lxc.rootfs.mount = <temporary rootfs mountpoint> ^ This is not to look for /var/lib/lxc/rootfs directory The error logs of LXC should be a lot better. Thanks for the strace debugging idea, it helped me a lot!
