You are probably thinking of a "storage driver"? https://docs.docker.com/v17.09/engine/userguide/storagedriver/selectadriver/ https://docs.docker.com/v17.09/en

You are probably thinking of a "storage driver"? https://docs.docker.com/v17.09/engine/userguide/storagedriver/selectadriver/ https://docs.docker.com/v17.09/engine/userguide/storagedrive...