path           = ? Any UNIX-like path ? ;
size           = ? Any non-negative multiple of 128000 (bytes) ? ;
fileBackend    = "file" , ";" , path ;
zfsBackend     = "zfs-volume" , [ ";" , size ] ;
storageBackend = fileBackend | zfsBackend ;

Examples:
  file;/tmp/xyz
  zfs-volume
  zfs-volume;1280000000
