All Docker containers and their data and metadata is stored under /var/lib/docker directory. By default, /var/lib/docker should be mounted under either the / or /var partitions dependent on how the Linux operating system in use is configured.


Docker depends on /var/lib/docker as the default directory where all Docker related files, including the images, are stored. This directory could fill up quickly causing both Docker and the host to become unusable. For this reason, you should create a separate partition (logical volume) for storing Docker files. [1]

For new installations, you should create a separate partition for the /var/lib/docker mount point. For systems which have already been installed, you should use the Logical Volume Manager (LVM) within Linux to create a new partition.