def test_find_mpath_members(self):
"""find_mpath_members enumerates kernel block devs of a mpath_id."""
mp_id = 'mpatha'
paths = ['device=bar multipath=mpatha', 'device=wark multipath=mpatha']
self.m_subp.return_value = ("\n".join(paths), "")
self.assertEqual(sorted(['/dev/bar', '/dev/wark']),
sorted(multipath.find_mpath_members(mp_id)))
def test_find_mpath_members_empty(self):
"""find_mpath_members returns empty list if mpath_id not found."""
mp_id = self.random_string()
paths = ['device=bar multipath=mpatha', 'device=wark multipath=mpatha']
self.m_subp.return_value = ("\n".join(paths), "")
self.assertEqual([], multipath.find_mpath_members(mp_id))
def lookup_disk(serial):
"""
Search for a disk by its serial number using /dev/disk/by-id/
"""
# Get all volumes in /dev/disk/by-id/ containing the serial string. The
# string specified can be either in the short or long serial format
# hack, some serials have spaces, udev usually converts ' ' -> '_'
serial_udev = serial.replace(' ', '_')
LOG.info('Processing serial %s via udev to %s', serial, serial_udev)
disks = list(
filter(lambda x: serial_udev in x, os.listdir("/dev/disk/by-id/")))
if not disks or len(disks) < 1:
raise ValueError("no disk with serial '%s' found" % serial_udev)
# Sort by length and take the shortest path name, as the longer path names
# will be the partitions on the disk. Then use os.path.realpath to
# determine the path to the block device in /dev/
disks.sort(key=lambda x: len(x))
LOG.debug('lookup_disks found: %s', disks)
path = os.path.realpath("/dev/disk/by-id/%s" % disks[0])
LOG.debug('lookup_disks realpath(%s)=%s', disks[0], path)
if multipath.is_mpath_device(path):
LOG.debug('Detected multipath device, finding a members')
info = udevadm_info(path)
mpath_members = sorted(multipath.find_mpath_members(info['DM_NAME']))
LOG.debug('mpath members: %s', mpath_members)
if len(mpath_members):
path = mpath_members[0]
if not os.path.exists(path):
raise ValueError("path '%s' to block device for disk with serial '%s' \
does not exist" % (path, serial_udev))
return path