Docker failing to start after migration

Insight & Feedback
1

Hello everyone.

Returning to linux after many years and enjoying Zima OS. but as you all know a little out-dated knowledge is a dangerous thing and I’m hoping for some advice to repair a broken install.

Context

ZimaOS HD in my system is a 180g SSD. due to my foolishness installign Immich I left the immich database on this drive. It of course filled up and threw and error.

Attempted migration via Zima OS to another drive but there was insufficent space on the OS HD to buffer. using forum posts I SSHed in and deleted .log files to create space and and migrated App data what i thought was successfully after a few failed attemps. Thanks to the forum communtiy for the posts that help the above.

The Error

When I rebooted docker failed to start. throwing this error when i try to run an app

Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?

using SSH trying to restart docker it get this

systemctl restart docker docker.socket
Failed to restart docker.service: Access denied
See system logs and ‘systemctl status docker.service’ for details.
Failed to restart docker.socket: Access denied
See system logs and ‘systemctl status docker.socket’ for details.

details of the failure

journalctl -u docker --no-pager | tail -50
Feb 03 18:35:07 ZimaOS systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
Feb 03 18:35:07 ZimaOS systemd[1]: docker.service: Failed with result ‘exit-code’.
Feb 03 18:35:07 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.
Feb 03 18:35:09 ZimaOS systemd[1]: docker.service: Scheduled restart job, restart counter is at 2.
Feb 03 18:35:09 ZimaOS systemd[1]: Starting Docker Application Container Engine…
Feb 03 18:35:09 ZimaOS dockerd[44575]: time=“2026-02-03T18:35:09.478964879+10:30” level=info msg=“Starting up”
Feb 03 18:35:09 ZimaOS dockerd[44575]: time=“2026-02-03T18:35:09.479445032+10:30” level=info msg=“OTEL tracing is not configured, using no-op tracer provider”
Feb 03 18:35:09 ZimaOS dockerd[44575]: time=“2026-02-03T18:35:09.479556737+10:30” level=warning msg=“failed to rename /var/lib/docker/tmp for background deletion: rename /var/lib/docker/tmp /var/lib/docker/tmp-old: file exists. Deleting synchronously”
Feb 03 18:35:09 ZimaOS dockerd[44575]: time=“2026-02-03T18:35:09.502184065+10:30” level=error msg=“mkdir /var/lib/docker/overlay2/check-overlayfs-support4087190078: no space left on device” storage-driver=overlay2
Feb 03 18:35:09 ZimaOS dockerd[44575]: time=“2026-02-03T18:35:09.502215871+10:30” level=error msg=“[graphdriver] prior storage driver overlay2 failed: driver not supported”
Feb 03 18:35:09 ZimaOS dockerd[44575]: failed to start daemon: error initializing graphdriver: driver not supported
Feb 03 18:35:09 ZimaOS systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
Feb 03 18:35:09 ZimaOS systemd[1]: docker.service: Failed with result ‘exit-code’.
Feb 03 18:35:09 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.
Feb 03 18:35:11 ZimaOS systemd[1]: docker.service: Scheduled restart job, restart counter is at 3.
Feb 03 18:35:11 ZimaOS systemd[1]: docker.service: Start request repeated too quickly.
Feb 03 18:35:11 ZimaOS systemd[1]: docker.service: Failed with result ‘exit-code’.
Feb 03 18:35:11 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.
– Boot de5cf76b7aac450db0d3a121c65f7ae7 –
Feb 04 04:26:48 ZimaOS systemd[1]: Starting Docker Application Container Engine…
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.349269107+10:30” level=info msg=“Starting up”
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.351973198+10:30” level=info msg=“OTEL tracing is not configured, using no-op tracer provider”
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.352324169+10:30” level=warning msg=“failed to rename /var/lib/docker/tmp for background deletion: rename /var/lib/docker/tmp /var/lib/docker/tmp-old: file exists. Deleting synchronously”
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.424333538+10:30” level=error msg=“Failed to ensure default apparmor profile is loaded” error=“AppArmor enabled on system but the docker-default profile could not be loaded: write /var/lib/docker/tmp/docker-default130330059: no space left on device”
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.447376127+10:30” level=error msg=“mkdir /var/lib/docker/overlay2/check-overlayfs-support134555568: no space left on device” storage-driver=overlay2
Feb 04 04:26:49 ZimaOS dockerd[1829]: time=“2026-02-04T04:26:49.447404787+10:30” level=error msg=“[graphdriver] prior storage driver overlay2 failed: driver not supported”
Feb 04 04:26:49 ZimaOS dockerd[1829]: failed to start daemon: error initializing graphdriver: driver not supported
Feb 04 04:26:49 ZimaOS systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
Feb 04 04:26:49 ZimaOS systemd[1]: docker.service: Failed with result ‘exit-code’.
Feb 04 04:26:49 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.
Feb 04 04:26:49 ZimaOS systemd[1]: docker.service: Consumed 153ms CPU time, 93.4M memory peak.
Feb 04 04:26:51 ZimaOS systemd[1]: docker.service: Scheduled restart job, restart counter is at 1.
Feb 04 04:26:51 ZimaOS systemd[1]: Starting Docker Application Container Engine…
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.753252083+10:30” level=info msg=“Starting up”
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.754029286+10:30” level=info msg=“OTEL tracing is not configured, using no-op tracer provider”
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.754240646+10:30” level=warning msg=“failed to rename /var/lib/docker/tmp for background deletion: rename /var/lib/docker/tmp /var/lib/docker/tmp-old: file exists. Deleting synchronously”
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.771557142+10:30” level=error msg=“Failed to ensure default apparmor profile is loaded” error=“AppArmor enabled on system but the docker-default profile could not be loaded: write /var/lib/docker/tmp/docker-default3759331356: no space left on device”
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.777913426+10:30” level=error msg=“mkdir /var/lib/docker/overlay2/check-overlayfs-support3232796386: no space left on device” storage-driver=overlay2
Feb 04 04:26:51 ZimaOS dockerd[2238]: time=“2026-02-04T04:26:51.777938293+10:30” level=error msg=“[graphdriver] prior storage driver overlay2 failed: driver not supported”
Feb 04 04:26:51 ZimaOS dockerd[2238]: failed to start daemon: error initializing graphdriver: driver not supported
Feb 04 04:26:51 ZimaOS systemd[1]: docker.service: Main process exited, code=exited, status=1/FAILURE
Feb 04 04:26:51 ZimaOS systemd[1]: docker.service: Failed with result ‘exit-code’.
Feb 04 04:26:51 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.
Feb 04 04:26:53 ZimaOS systemd[1]: Stopped Docker Application Container Engine.
Feb 04 04:26:53 ZimaOS systemd[1]: Starting Docker Application Container Engine…
Feb 04 04:26:53 ZimaOS systemd[1]: docker.service: Deactivated successfully.
Feb 04 04:26:53 ZimaOS systemd[1]: Stopped Docker Application Container Engine.
Feb 04 04:26:53 ZimaOS systemd[1]: docker.service: Start request repeated too quickly.
Feb 04 04:26:53 ZimaOS systemd[1]: docker.service: Failed with result ‘start-limit-hit’.
Feb 04 04:26:53 ZimaOS systemd[1]: Failed to start Docker Application Container Engine.

Any advice appreciated, haven’t used docker much and a forum search hasn’t shown many options other than the SSH manaual start (which fails)

thanks.

system details for reference

ZimaOS v1.5.3 Plus

CPU

intel(R) N150

4 Cores2.90 GHz 4 Threads

RAM

1 RAM 16 GB total

4800 MHzDDR5

GPU

Intel Corporation Alder Lake-N [Intel Graphics]

2

Your logs clearly show “no space left on device” on the root/overlay filesystem, not AppData. On ZimaOS, /var/lib/docker lives on the OS overlay and is not moved by the AppData migration tool. Docker needs free space there just to start (overlay checks, tmp files, AppArmor), so once the OS disk filled up, Docker can’t even come up.

Why the commands behave oddly:

  • systemctl restart docker → Access denied is expected on ZimaOS (immutable OS).
  • Docker is aborting during init due to lack of space, not permissions.

What to try first (safe, non-destructive):

  1. Confirm it:
df -h /
df -i /
  1. Clear Docker temp files:
rm -rf /var/lib/docker/tmp/*
  1. Reboot.

If Docker still won’t start, the overlay metadata is likely corrupted from being 100% full. At that point, the most reliable fix (and common ZimaOS advice) is:

  • Back up /DATA/AppData
  • Reinstall ZimaOS (system disk only)
  • Immediately migrate AppData + images to the large disk before reinstalling apps

Unfortunately this is a known gotcha on ZimaOS/CasaOS when the OS disk fills completely.

3

Hi Gelbuilding,

Thanks for the guidance, relatively new to Zima and the oversight on database location certainly filled the OS Drive.

you are correct I checked as outlined the OS drive is 100% and clearing the Docker Tmp files did not resolve.

I’ll back uo /DATA/AppData and reinstall.

is there a detailed guide on this as I’m still fairly unfamilar with Zima and will fall for the beginner mistakes :slight_smile:

4

I’ve posted a write-up of this recovery method before (can’t seem to locate it right now), but in short this is exactly what you need to do.

Once the OS disk/overlay fills up, the fastest and most reliable fix is a Factory System Restore.

After a factory restore, all apps will be removed, but your data disks are not touched.
Before starting, make a note of all installed apps so you can reinstall them afterward.

Where to find Factory System Restore
ZimaOS Web UI > Settings > System > Factory System Restore

Steps after the restore

  1. On first boot (before installing any apps), migrate all three sections to your large data disk:
  • AppData
  • Docker Images
  • Data / Downloads
  1. Reinstall your apps from the App Store, they will automatically reuse the existing AppData.

This avoids fighting a corrupted OS overlay and prevents the issue from happening again.
It’s a known ZimaOS limitation once the system disk hits 100%, not user error.

1 Like
5

Thanks Gelbuilding much appreciated will do.