The centos dockerfile has a default command bash. That means, when run in background (-d), the shell exits immediately. Update 2017 More recent versions of docker authorize to run a container both in detached mode and in foreground mode (-t, -i or -it) In that case, you don’t need any additional command and this is … Read more
(original answer see below) Update Sept. 2016: Docker 1.13: PR 26108 and commit 86de7c0 introduce a few new commands to help facilitate visualizing how much space the docker daemon data is taking on disk and allowing for easily cleaning up “unneeded” excess. docker system prune will delete ALL dangling data (i.e. In order: containers stopped, … Read more
The contents of the /var/lib/docker directory vary depending on the driver Docker is using for storage. By default this will be aufs but can fall back to overlay, overlay2, btrfs, devicemapper or zfs depending on your kernel support. In most places this will be aufs but the RedHats went with devicemapper. You can manually set … Read more