Fix cAdvisor Containerd Namespace Mismatch with Docker 29

If you upgraded to Docker 29 and your cAdvisor container metrics stopped showing up, the issue is a containerd namespace mismatch — not a storage driver problem.

The Problem

Docker 29 defaults to the containerd image store, which replaces the legacy graphdriver (overlay2) layerdb layout with containerd’s native image management. When cAdvisor runs in containerd mode, it defaults to the k8s.io containerd namespace — but Docker creates containers under the moby namespace. The result: cAdvisor sees zero containers.

Quick Fix

# Run cAdvisor pointing at the moby namespace
docker run -d \
  --name=cadvisor \
  --volume=/:/rootfs:ro \
  --volume=/var/run/docker.sock:/var/run/docker.sock:ro \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  --volume=/run/containerd/containerd.sock:/run/containerd/containerd.sock:ro \
  --network=host \
  gcr.io/cadvisor/cadvisor:latest \
  --containerd \
  --containerd-namespace=moby

The key flags are:

• --containerd-namespace=moby — tells cAdvisor to read the moby namespace, not k8s.io
• --containerd — enables containerd mode instead of the legacy Docker socket mode
• --volume=/run/containerd/containerd.sock:/run/containerd/containerd.sock:ro — mounts the containerd socket

How to Verify the Correct Namespace

If moby doesn’t work, check what namespace your Docker daemon is using:

# List all containerd namespaces
ctr --address /run/containerd/containerd.sock ns ls

# List containers in the moby namespace
ctr --address /run/containerd/containerd.sock -n moby containers ls

# List images in the moby namespace
ctr --address /run/containerd/containerd.sock -n moby images ls

You should see Docker containers listed under the moby namespace. If your Docker daemon uses a different namespace, adjust accordingly.

Docker Compose Version

For Docker Compose, add the namespace and containerd flags as command arguments:

services:
  cadvisor:
    image: gcr.io/cadvisor/cadvisor:latest
    volumes:
      - /:/rootfs:ro
      - /var/run/docker.sock:/var/run/docker.sock:ro
      - /sys:/sys:ro
      - /var/lib/docker/:/var/lib/docker:ro
      - /run/containerd/containerd.sock:/run/containerd/containerd.sock:ro
    network_mode: host
    command:
      - '--containerd'
      - '--containerd-namespace=moby'
    privileged: true

Root Cause: Why This Happens

Docker 29’s New Image Store

Docker 29 (both Docker Engine and Docker Desktop) ships with the containerd image store enabled by default. This replaces:

cAdvisor’s Default Namespace

cAdvisor’s containerd integration defaults to the k8s.io namespace — the namespace used by Kubernetes when it embeds containerd. When you run cAdvisor next to Docker (not Kubernetes), that default is wrong. You must explicitly set --containerd-namespace=moby.

Alternative: Docker Socket Mode

If you want to avoid the containerd namespace issue entirely, run cAdvisor in Docker socket mode instead of containerd mode:

docker run -d \
  --name=cadvisor \
  --volume=/:/rootfs:ro \
  --volume=/var/run/docker.sock:/var/run/docker.sock:ro \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  --network=host \
  --privileged \
  gcr.io/cadvisor/cadvisor:latest

Without the --containerd flag, cAdvisor falls back to reading the Docker socket, which abstracts away the containerd namespace detail. The trade-off: you get Docker-level container visibility but lose the granular containerd image and snapshot metrics.

Environment Variables (Alternative)

You can also set the namespace via environment variable if your cAdvisor setup supports it:

export CONTAINERD_NAMESPACE=moby

Or in Docker Compose:

environment:
  - CONTAINERD_NAMESPACE=moby

Related Resources

• Docker Cheat Sheet
• Docker Storage Driver Troubleshooting
• Docker Security Best Practices
• Docker vs Kubernetes

About the Author

I am Luca Berton, AI and Cloud Advisor. I help teams debug and optimize their container infrastructure. Book a consultation to fix your Docker issues.