[HOW-TO] Proxmox 7 cgroupv2 - Centos 7 upgrade systemd without systemd.unified_cgroup_hierarchy=0

[timonych]

Hi Everyone!

I have found an easy workaround how upgrade Centos 7 systemd without modify grub and without reboot host.

So, You should do a few steps.

Disclaimer 1, it's HIGHLY recommended to switch to modern distr which has actual systemd with natively support cgroup v2!!!!

Disclaimer 2, all examples is directed to modify container with ID 100, LVM storage and volume group VG-IMAGES

1. Making dir for mount

mkdir -p /mnt/virtual100

2. Mount a container base image.

mount /dev/vg-images/vm-100-disk-0 /mnt/virtual100

3. Mount neccessary DEV, PROC, SYS to container

mount --bind /dev/ /mnt/virtual100/dev
mount --bind /dev/pts /mnt/virtual100/dev/pts
mount --bind /proc /mnt/virtual100/proc
mount --bind /sys /mnt/virtual100/sys

4. Entering to container via chroot

chroot /mnt/virtual100

5. Download repo with systemd with cgroup v2

wget https://copr.fedorainfracloud.org/coprs/jsynacek/systemd-backports-for-centos-7/repo/epel-7/jsynacek-systemd-backports-for-centos-7-epel-7.repo -O /etc/yum.repos.d/jsynacek-systemd-centos-7.repo

6. Update all packages to actual

yum update

7. Exit from chroot and unmount DEV, PROC, SYS, Container Image

exit
umount /dev/virtual100/dev/pts
umount /dev/virtual100/dev
umount /dev/virtual100/proc
umount /dev/virtual100/sys
umount /dev/virtual100

7. Start Your container

pct start 100

Spoiler: Screenshot

 

[digidax]

Will this procedure make it possible to run Centos 7 in LXC containter under Proxmox 7?

 

[timonych]

Will this procedure make it possible to run Centos 7 in LXC containter under Proxmox 7?

Why not?

Contaier will be worked as before, but it's not recommended to use in PRODUCTION.

Linux Oracle 5.11.22-5-pve #1 SMP PVE 5.11.22-10 (Tue, 28 Sep 2021 08:15:41 +0200) x86_64 x86_64 x86_64 GNU/Linux

Spoiler: Screenshot

 

[timonych]

By the way.

If You want to use this workaround for multiple containers in future - I'll recommend to make this only for one, mak backup of this container and after restore this backup like template (restore backup to another VMID)

 

[Baulder]

Great HOW-TO!

Don't forget to unmount vm image before starting your container (maybe error in your last umount line?):

umount /mnt/virtual100

 

[timonych]

Great HOW-TO!

Don't forget to unmount vm image before starting your container (maybe error in your last umount line?):

umount /mnt/virtual100

Hi!

You are right, It's mistake, but I can't edit this

 

[mmartin]

Nice solution. For me was more easy work with started container and:

wget https://copr.fedorainfracloud.org/c...ek-systemd-backports-for-centos-7-epel-7.repo -O /etc/yum.repos.d/jsynacek-systemd-centos-7.repo

and

yum update systemd

restart the container from the web o cli

 

[scracha]

You sir, are a scholar and a gent

mount /dev/pve/vm-100-disk-0 /mnt/virtual100