Homeassistant.cid was missing and therefore container could not be started

StefanC · April 28, 2026, 10:02am

I recently had a problem where my Home Assistant Raspberry Pi installation lost wifi connection, which I’ve had a few times and I put it down to a bad wifi adapter. So, given there was no way to get in to the system, I unplugged it and plugged it back in.

Then on power up home assistant would not start, although I could see my Pi device on the network. After being able to SSH to root and investigate the supervisor container - which was running - I could see there was an error “bind source path does not exist: /mnt/data/supervisor/cid_files/homeassistant.cid”, and the homeassistant container could not be started.

I could see that the file /mnt/data/supervisor/cid_files/homeassistant.cid did not exist on my host, which would be why the homeassistant container doesn’t start. But reviewing the supervisor manager.py source code, I see that this file should be created every time supervisor starts.

github.com/home-assistant/supervisor

supervisor/docker/manager.py

ee1c6c48f


      
          ) -> DockerContainer:
              """Create a Docker container and run it."""
              if not image or not tag:
                  raise ValueError("image and tag cannot be an empty string!")
          
              cidfile_path: Path | None = None
              if name and not skip_cidfile:
                  # Setup cidfile and bind mount it
                  cidfile_path = self.coresys.config.path_cid_files / f"{name}.cid"
          
                  def create_cidfile() -> None:
                      # Remove the file/directory if it exists e.g. as a leftover from unclean shutdown
                      # Note: Can be a directory if Docker auto-started container with restart policy
                      # before Supervisor could write the CID file
                      with suppress(OSError):
                          if cidfile_path.is_dir():
                              cidfile_path.rmdir()
                          elif cidfile_path.is_file():
                              cidfile_path.unlink(missing_ok=True)
          
                      # Create empty CID file before adding it to volumes to prevent Docker

How is it possible that the .cid file could not be added?

For now I have manually created the file with touch and now my homeassistant starts up, but I’m worried this will occur again the future.

Sir_Goodenough · April 28, 2026, 2:22pm

Hello Stefan,
I do not suggest Running your HA server on WIFI at all, it is often the root of other problems, but that said…

If When you come back for help here, please let the person helping know your server is on WIFI.

ShadowFist · April 29, 2026, 11:42am

In addition to the not using wifi advice above, don’t pull power on a running system either. If you have to reboot or shutdown, connect a monitor & keyboard to your Pi & run the host reboot/shutdown commands listed here via CLI.

Try running ha supervisor repair & ha supervisor restart via CLI. Hopefully that should fix your issue.