def _open_lvm(self):
        os.environ['LVM_SUPPRESS_FD_WARNINGS'] = '1'

        # find free loopback device
        if not self._find_loopback():
            return False

        time.sleep(0.2)

        # Scan for new lvm volumes
        result = _util.check_output_(["lvm", "pvscan"])
        for l in result.splitlines():
            if self.loopback in l or (self.offset == 0 and self.get_raw_path() in l):
                for vg in re.findall(r'VG (\S+)', l):
                    self.volume_group = vg

        if not self.volume_group:
            logger.warning("Volume is not a volume group. (Searching for %s)", self.loopback)
            return False

        # Enable lvm volumes
        _util.check_call_(["lvm", "vgchange", "-a", "y", self.volume_group], stdout=subprocess.PIPE)

        return True
If a player is standing I{next} to a dark room, they should not be able
dataset/ETHPy150Open ralphje/imagemounter/imagemounter/volume.py/Volume._open_lvm--crossover with--dataset/ETHPy150Open twisted/imaginary/imaginary/test/test_illumination.py/ActionsInDarkRoomTestCase.test_actionWithTargetInAdjacentDarkRoom