First I want to start to say that we are still trying to reproduce the issue. Because we had this on production systems we did not had the luxury to do a lot of investigation before executing the workaround. A reboot solves the issue, so that is done as soon as possible after we are triggered with this issue.

The issue we have:
We have about 200 coreos systems which are automatically updated with new coreos releases. During the day the new coreos image is installed. Then we have the locksmith with the reboot strategy=reboot and a window between 02:00 and 04:00 AM.

During that reboot we see that there are issues unmounting /run/torcx/unpack.
Aug 03 02:05:26 slnc7r1306 systemd[1]: run-torcx-unpack.mount: Mount process exited, code=exited, status=32/n/a
Aug 03 02:05:26 slnc7r1306 systemd[1]: Failed unmounting /run/torcx/unpack.

then the shutdown continues and coreos is booting from the updated partition.

After the reboot docker wil not start and we can't do anything with docker. It will generates torcx error messages. After a reboot of the the system it works fine.

TO ADD
- log the exact message we see when running into this issue
- show states of the two torcx services
more?
TO ADD

Until now we encountered this issue randomly over the 200 systems. Not during every new coreos update, but during the most of the updates we random have 1 or 2 systems running into this issue.

I hope you can help us to find / solve this issue.