Bug#981101: cgroup is not mounted

[shan.bharani at gmail.com]

Hi Michael,

I too have filed bug with lxc maintainers. 

I did try to change unified to false in a Virtual Machine in Gnome
Boxes to test(*), however systemd reports only unified after change. (
output of systemd --version). I will try change it in host if it works
fine with VM.

I also did fresh installs in VM to test systemd and lxc it never
worked. However systemd and lxc works for earlier versions.(
Bullseye/Sid Kernel 5.9 )

Will wait for updates from lxc team if any.

(*)(i) Updated the grub file with
GRUB_CMDLINE_LINUX="systemd.unified_cgroup_hierarchy=false"
(ii) ran update-grub
(iii) reboot
(iv) systemd --version

Regards,
Bharani

On Tue, 2021-01-26 at 13:57 +0100, Michael Biebl wrote:
> Am 26.01.21 um 13:53 schrieb shan.bharani at gmail.com:
> > Hi Michael,
> > 
> > Shouldn't "/sys/fs/cgroup/unified" be mounted by systemd to be used
> > lxc
> > to use cgroupv2?
> > 
> > Should we need to do "mount -t tmpfs cgroup /sys/fs/cgroup" for
> > cgroupv2 as well? Will it be done systemd ?
> > 
> > In cgroupv1, it is usually seen "/sys/fs/cgroup" mounted on tmpfs.
> > In
> > case of cgroupv2 unified, nothing like that is seen.
> > 
> > 
> > df -h
> > Filesystem      Size  Used Avail Use% Mounted on
> > udev            3.4G     0  3.4G   0% /dev
> > tmpfs           692M  1.7M  691M   1% /run
> > /dev/sda8       125G   57G   62G  48% /
> > tmpfs           3.4G     0  3.4G   0% /dev/shm
> > tmpfs           5.0M  4.0K  5.0M   1% /run/lock
> > /dev/sda1        96M   62M   35M  65% /boot/efi
> > tmpfs           692M  212K  692M   1% /run/user/1000
> > 
> > 
> > 
> > Please note that lxc and lxcfs is malfunctioning for fresh installs
> > (Linux coffee 5.10.0-1-amd64 #1 SMP Debian 5.10.4-1 (2020-12-31)
> > x86_64
> > GNU/Linux) as well. Not sure which package is having problem. But
> > its(lxc) not working.
> 
> I can not confirm that.
> lxc is working fine here ootb with cgroupv2.
> No changes necessary, no manual mounts or anything.
> 
> The only known issue I'm aware of, is if you want to run jessie 
> containers on a bullseye/sid host.
> Since jessie's systemd does not yet support cgroupv2, you need to
> switch 
> the host back to unified if you want to use such containers.
> 
> Maybe you have some custom config, which breaks lxc. The lxc
> maintainers 
> will be in a better situation to help you debug that.
> 
> Regards,
> Michael
> 
> 
>