slackbuilds_ponce/system/local-persist

Local-persist is a docker plugin that provides persistent local volumes.
This gives you the same benefits of standalone volumes that "docker
volume create" normally affords, while also allowing you to create
volumes that persist in arbitrary disk locations.

Warning: This SlackBuild requires network access when it runs, meaning
it downloads files from the Internet with root access. You should
decide for yourself whether or not you think this is a good idea.