An implementation of the storagedriver.StorageDriver interface which uses the local filesystem.
rootdirectory: (optional) The absolute path to a root directory tree in which
to store all registry files. The registry stores all its data here so make sure
there is adequate space available. Defaults to /var/lib/registry.
maxthreads: (optional) The maximum number of simultaneous blocking filesystem
operations permitted within the registry. Each operation spawns a new thread and
may cause thread exhaustion issues if many are done in parallel. Defaults to
100, and can be no lower than 25.