コピペ: docker overlay2 folder cleanup

形式

Plain text

投稿日時

2023-08-02 18:42

公開期間

無期限

 2023-08-01
 What happens is that sometimes the /var/lib/docker/overlay2 folder gets filled with subfolders and its size increase.
 
 No amount of `docker system prune -a -f` or 'docker image prune -a' or 'docker buildx prune -a' or similar command is able to clean up everything. A good chunk of subfolders stay there.
 
 So what to do?
 
 As of today, the overlay2 folder contains subfolders that represent container layers. If while building an image a middle step was creating data during the build process, that layer is saved and stored in the overlay2 folder.
 It would be like /var/lib/docker/overlay2/<some hash>/diff/<data here> .
 Now this should be deleted with image prune -a or the cache prune. But it is not, because somehow those folder gets orphaned.
 
 One approach is the following. (if one can delete everything)
 - Stop the docker service.
 - list the docker packages in the system, for example: yum list installed | grep -i docker
 - remove them (yum remove <packages>)
 - then move /var/lib/docker to /tmp
 - reinstall the packages
 - ensure that docker works
 - remove /tmp/docker
 
 If you cannot remove everything:
 - stop the docker service
 - Collect all the folder names that are hashes. 
 - then you can try to delete the content saved by the container, removing entries in each /var/lib/docker/overlay2/<hash>/diff/<content that can be removed>
 - restart the docker service
 - do some tests, it should work.