def _OpenRealBD(disk):
  real_disk = _RecursiveFindBD(disk)
  if real_disk is None:
    _Fail("Block device '%s' is not set up", disk)

  real_disk.Open()

  return real_disk
Opens the underlying block device of a disk.
dataset/ETHPy150Open ganeti/ganeti/lib/backend.py/_OpenRealBD