sudo docker start mydocker
Error response from daemon: error creating overlay mount to /var/lib/docker/overlay2/b9c8e9b7d30…/merged: no such file or directory
Error: failed to start containers:mydocker
It depends on the cause but I don’t think that you can restart it. This error could happen when the container’s filesystem folder or the “merged” folder is missing. The reason could be a damaged disk which corrupted the filesystem, or something (or someone) edited the files without using Docker, or maybe Docker itself had an interrupted I/O operation. Even though there could be a way to fix it, it would require someone who knows exactly how the overlay filesystem works and How Docker stores its own metadata related to the container. I don’t think that “saving” a container is worth that effort. Containers should be stateless in a way that you don’t store anything important on the container’s filesystem so you have everything on volumes or in databases and you can just delete the container and start an other.