Ubuntu 22.04 Docker Daemon Fails with cgroup v2 Configuration Errors

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Docker service fails to start, preventing container workloads from running on Ubuntu 22.04.

Environment & Reproduction

Ubuntu 22.04 defaults to unified cgroup v2; reproduce with incompatible daemon.json cgroup driver or old runtime assumptions.

Root Cause Analysis

Mismatch between Docker, containerd, and systemd cgroup modes causes daemon startup errors and controller mount issues.

Quick Triage

Run docker info if available, inspect sudo systemctl status docker, and check /proc/filesystems and /sys/fs/cgroup layout.

Step-by-Step Diagnosis

Review journalctl -u docker, inspect /etc/docker/daemon.json, and validate containerd config for systemd cgroup compatibility.

Solution – Primary Fix

Set Docker to use systemd cgroup driver on Ubuntu 22.04, restart containerd and docker, then revalidate with docker info.

Solution – Alternative Approaches

Upgrade Docker/runtime packages, migrate to supported distro packages, or pin known-good versions in production.

Verification & Acceptance Criteria

docker service is active, test container launches successfully, and cgroup driver values are consistent across components.

Rollback Plan

Restore previous daemon/containerd config files and restart services if compatibility regressions appear.

Prevention & Hardening

Document cgroup mode standards, validate runtime configs in CI, and monitor daemon health after kernel updates.

Related Errors & Cross-Refs

Related Ubuntu 22.04 container problems include UFW chain conflicts and overlay2 filesystem mount errors.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Docker docs for Ubuntu, systemd cgroup v2 documentation, and containerd configuration guides.