[SOLVED] LXC, Debian 10, Docker does not start: Devices cgroup isn't mounted

[JoeSix]

Hi,

just upgraded my Proxmox 6 instance to version 7 and now a docker instance running in a Debian 10 based unprivileged container does not start anymore:

dockerd[474]: Error starting daemon: Devices cgroup isn't mounted

$ systemctl status docker.service
* docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Tue 2021-07-27 09:19:28 CEST; 5min ago
     Docs: https://docs.docker.com
  Process: 474 ExecStart=/usr/sbin/dockerd -H fd:// $DOCKER_OPTS (code=exited, status=1/FAILURE)
 Main PID: 474 (code=exited, status=1/FAILURE)
      CPU: 201ms

Jul 27 09:19:28 pwsync systemd[1]: docker.service: Failed with result 'exit-code'.
Jul 27 09:19:28 pwsync systemd[1]: Failed to start Docker Application Container Engine.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Consumed 201ms CPU time.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Service RestartSec=100ms expired, scheduling restart.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Scheduled restart job, restart counter is at 3.
Jul 27 09:19:28 pwsync systemd[1]: Stopped Docker Application Container Engine.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Consumed 201ms CPU time.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Start request repeated too quickly.
Jul 27 09:19:28 pwsync systemd[1]: docker.service: Failed with result 'exit-code'.
Jul 27 09:19:28 pwsync systemd[1]: Failed to start Docker Application Container Engine.

$ pveversion
pve-manager/7.0-10/d2f465d3 (running kernel: 5.11.22-2-pve)

$ cat /etc/pve/lxc/104.conf
arch: amd64
cores: 2
features: keyctl=1,nesting=1
hostname: demo
memory: 2048
net0: name=eth0,bridge=vmbr0,firewall=1,gw=192.168.173.1,hwaddr=6E:B6:04:1C:3B:61,ip=192.168.173.207/24,type=veth
onboot: 0
ostype: debian
protection: 1
rootfs: disk02:104/vm-104-disk-1.raw,size=20G
swap: 2048
unprivileged: 1

The hints according to CentOS 7/8 problems mentioned in other threads did not solved this issue.

Any ideas what´s going wrong here?

 

[JoeSix]

Meanwhile I was able to solve the issue myself. Problem was simple, Docker version included in Debain 10 is outdated completely. Upgrading in LXC to latest Docker-CE edtion fixed the problems:

https://docs.docker.com/engine/install/debian/