Repository navigation
[BUG] Kasm does not start after an unclean shutdown when the stale containerd pid belongs to another process #110
Description
Is there an existing issue for this?
- I have searched the existing issues
Current Behavior
/run is not a tmpfs in this image, so after an unclean shutdown (docker kill, power loss, OOM kill), /run/docker/containerd/containerd.pid is still there when the container starts again. dockerd-entrypoint.sh only deletes docker*.pid. If another process has been given that pid by the time dockerd starts, dockerd takes it for a running containerd (moby, pidfile.Read), never starts its own and gives up with failed to start containerd: timeout waiting for containerd to start. s6 restarts it, and it fails again for as long as that process lives.
svc-kasm/run only waits for /var/run/docker.sock to exist, so it goes on without dockerd and fails (unable to start service svc-kasm: command exited 1). Once dockerd does start, the Kasm containers come back through their restart policy, but svc-kasm stays failed, so svc-kasm/finish does not run on the next stop.
I hit it once after docker kill kasm and docker start kasm. Pointing the pid file at a process that always exists reproduces it every time.
Expected Behavior
Kasm starts after an unclean shutdown.
Steps To Reproduce
- Let Kasm start.
docker kill kasm- Make the stale pid point at a live process (pid 1 always exists):
echo 1 > containerd.pid && docker cp containerd.pid kasm:/run/docker/containerd/containerd.pid docker start kasm: the log loops onfailed to start containerd: timeout waiting for containerd to start,svc-kasmfails, and Kasm stays down.
Environment
- OS: Ubuntu 24.04.4 LTS (kernel 6.18, cgroup v1)
- How docker service was installed: docker-ce 29.3.1 from Docker's apt repository
- Workspace image: kasmweb/remmina:1.19.0-rolling-dailyCPU architecture
x86-64
Docker creation
docker run -d --name kasm --privileged --network host --stop-timeout 90 \
-e KASM_PORT=443 \
-v /path/to/kasm/data:/opt \
lscr.io/linuxserver/kasm:1.19.0-ls150
# plus HTTPS_PROXY and a CA bundle for the test VM's egress proxyContainer logs
[migrations] started
[migrations] no migrations found
usermod: no changes
───────────────────────────────────────
██╗ ███████╗██╗ ██████╗
██║ ██╔════╝██║██╔═══██╗
██║ ███████╗██║██║ ██║
██║ ╚════██║██║██║ ██║
███████╗███████║██║╚██████╔╝
╚══════╝╚══════╝╚═╝ ╚═════╝
Brought to you by linuxserver.io
───────────────────────────────────────
To support LSIO projects visit:
https://www.linuxserver.io/donate/
───────────────────────────────────────
GID/UID
───────────────────────────────────────
User UID: 911
User GID: 911
───────────────────────────────────────
Linuxserver.io version: 1.19.0-ls150
Build-date: 2026-09-22T23:50:52+00:00
───────────────────────────────────────
[custom-init] No custom files found, skipping...
Failed to fetch workspace list, falling back to local list.json: fetch failed
failed to start containerd: timeout waiting for containerd to start
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
Pulling Latest Kasm Service Images
time="2026-09-23T12:47:32Z" level=warning msg="/opt/kasm/1.19.0/docker/docker-compose.yaml: the attribute `version` is obsolete, it will be ignored, please remove it to avoid potential confusion"
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
Upgrading rolling plugins
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
Starting Kasm Services
time="2026-09-23T12:47:32Z" level=warning msg="/opt/kasm/1.19.0/docker/docker-compose.yaml: the attribute `version` is obsolete, it will be ignored, please remove it to avoid potential confusion"
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
s6-rc: warning: unable to start service svc-kasm: command exited 1
failed to start containerd: timeout waiting for containerd to start
failed to start containerd: timeout waiting for containerd to start
failed to start containerd: timeout waiting for containerd to start
failed to start containerd: timeout waiting for containerd to start
failed to start containerd: timeout waiting for containerd to start
failed to start containerd: timeout waiting for containerd to start
Activity
LinuxServer-CI commentedon Oct 23, 2026
This issue has been automatically marked as stale because it has not had recent activity. This might be due to missing feedback from OP. It will be closed if no further activity occurs. Thank you for your contributions.