openstack/diskimage-builder
Code Issues Proposed changes

Merge "Reduce LVM extent usage"

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This commit is contained in:
Zuul 2024-10-22 16:27:09 +00:00 committed by Gerrit Code Review
commit 428901ef58
2 changed files with 69 additions and 16 deletions
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32
diskimage_builder/elements/growvols/static/usr/local/sbin/growvols
View File

@ -191,6 +191,31 @@ def convert_bytes(num):
return "%d%s" % (unit_num, x)
def shrink_bytes_for_alignment(num):
"""Shrink the amount of bytes to line up with LVM.
The purpose of this method is to gently shrink the requested volume
size of bytes to ensure that the size of the bytes range is in alignment
with the LVM extent size, and that the bytes value used is modeled in
the concept of extents where *two* extents have also been removed from
the value to account for any possible structural alignment differences
due to varying block sizes. In other words, reduce the size slightly to
account for the differences.
:param: num as in the number of bytes desired.
:returns: The closest value accounting for extent sizing *minus* two LVM
extents.
"""
result = ((num // PHYSICAL_EXTENT_BYTES) - 2) * PHYSICAL_EXTENT_BYTES
if result <= 0:
raise Exception(
'Not enough space available to shrink to alignment. '
'Requires more than %s, requested: %s' % (
convert_bytes(PHYSICAL_EXTENT_BYTES * 2),
convert_bytes(num)))
return result
def execute(cmd):
"""Run a command"""
LOG.info('Running: %s', printable_cmd(cmd))
@ -542,7 +567,8 @@ def main(argv):
devname = find_next_device_name(devices, disk, partnum)
thin_pool, thin_pool_name = find_thin_pool(devices, group)
if thin_pool:
# reserve for the size of the metadata volume
# reserve for the size of the metadata volume, which
# is *allocated* from the underlying storage as well.
size_bytes -= POOL_METADATA_SIZE
# reserve for the size of the spare metadata volume,
# used for metadata check and repair
@ -598,7 +624,7 @@ def main(argv):
convert_bytes(POOL_METADATA_SIZE), thin_pool)))
commands.append(Command([
'lvextend',
'-L+%sB' % size_bytes,
'-L+%sB' % shrink_bytes_for_alignment(size_bytes),
thin_pool,
dev_path
], 'Add %s to thin pool %s' % (convert_bytes(size_bytes),
@ -609,7 +635,7 @@ def main(argv):
extend_args = [
'lvextend',
'--size',
'+%sB' % size_bytes,
'+%sB' % shrink_bytes_for_alignment(size_bytes),
volume_path
]
if not thin_pool:

51
diskimage_builder/elements/growvols/tests/test_growvols.py
View File

@ -279,6 +279,33 @@ class TestGrowvols(base.BaseTestCase):
self.assertEqual('2GiB', growvols.convert_bytes(3000000000))
self.assertEqual('3725GiB', growvols.convert_bytes(4000000000000))
def test_shrink_bytes_for_alignment(self):
peb = growvols.PHYSICAL_EXTENT_BYTES
half_peb = peb // 2
# shrink 3 extents to 1
self.assertEqual(peb, growvols.shrink_bytes_for_alignment(peb * 3))
# shrink 4.5 extents to 2 (round down to whole extent minus 2 extents)
self.assertEqual(peb * 2,
growvols.shrink_bytes_for_alignment(
peb * 4 + half_peb))
# error shrinking zero
e = self.assertRaises(Exception,
growvols.shrink_bytes_for_alignment, 0)
self.assertIn('Requires more than 8MiB, requested: 0B', str(e))
# error shrinking 1 extent
e = self.assertRaises(Exception,
growvols.shrink_bytes_for_alignment, peb)
self.assertIn('Requires more than 8MiB, requested: 4MiB', str(e))
# error shrinking 2 extents
e = self.assertRaises(Exception,
growvols.shrink_bytes_for_alignment, peb * 2)
self.assertIn('Requires more than 8MiB, requested: 8MiB', str(e))
@mock.patch('subprocess.Popen')
def test_execute(self, mock_popen):
mock_process = mock.Mock()
@ -728,7 +755,7 @@ class TestGrowvols(base.BaseTestCase):
mock.call(['partprobe']),
mock.call(['pvcreate', '-ff', '--yes', '/dev/sda5']),
mock.call(['vgextend', 'vg', '/dev/sda5']),
mock.call(['lvextend', '--size', '+209404821504B',
mock.call(['lvextend', '--size', '+209396432896B',
'/dev/mapper/vg-lv_root', '/dev/sda5']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_root'])
])
@ -759,11 +786,11 @@ class TestGrowvols(base.BaseTestCase):
mock.call(['partprobe']),
mock.call(['pvcreate', '-ff', '--yes', '/dev/sda5']),
mock.call(['vgextend', 'vg', '/dev/sda5']),
mock.call(['lvextend', '--size', '+41880125440B',
mock.call(['lvextend', '--size', '+41871736832B',
'/dev/mapper/vg-lv_home', '/dev/sda5']),
mock.call(['lvextend', '--size', '+83760250880B',
mock.call(['lvextend', '--size', '+83751862272B',
'/dev/mapper/vg-lv_var', '/dev/sda5']),
mock.call(['lvextend', '--size', '+83764445184B',
mock.call(['lvextend', '--size', '+83756056576B',
'/dev/mapper/vg-lv_root', '/dev/sda5']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_home']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_var']),
@ -832,13 +859,13 @@ class TestGrowvols(base.BaseTestCase):
mock.call(['vgextend', 'vg', '/dev/sda5']),
mock.call(['lvextend', '--poolmetadatasize', '+1073741824B',
'vg/lv_thinpool']),
mock.call(['lvextend', '-L+207253143552B',
mock.call(['lvextend', '-L+207244754944B',
'/dev/mapper/vg-lv_thinpool', '/dev/sda5']),
mock.call(['lvextend', '--size', '+41448112128B',
mock.call(['lvextend', '--size', '+41439723520B',
'/dev/mapper/vg-lv_home']),
mock.call(['lvextend', '--size', '+82900418560B',
mock.call(['lvextend', '--size', '+82892029952B',
'/dev/mapper/vg-lv_var']),
mock.call(['lvextend', '--size', '+82904612864B',
mock.call(['lvextend', '--size', '+82896224256B',
'/dev/mapper/vg-lv_root']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_home']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_var']),
@ -881,13 +908,13 @@ class TestGrowvols(base.BaseTestCase):
mock.call(['vgextend', 'vg', '/dev/mapper/mpatha6']),
mock.call(['lvextend', '--poolmetadatasize', '+1073741824B',
'vg/lv_thinpool']),
mock.call(['lvextend', '-L+207253143552B',
mock.call(['lvextend', '-L+207244754944B',
'/dev/mapper/vg-lv_thinpool', '/dev/mapper/mpatha6']),
mock.call(['lvextend', '--size', '+41448112128B',
mock.call(['lvextend', '--size', '+41439723520B',
'/dev/mapper/vg-lv_home']),
mock.call(['lvextend', '--size', '+82900418560B',
mock.call(['lvextend', '--size', '+82892029952B',
'/dev/mapper/vg-lv_var']),
mock.call(['lvextend', '--size', '+82904612864B',
mock.call(['lvextend', '--size', '+82896224256B',
'/dev/mapper/vg-lv_root']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_home']),
mock.call(['xfs_growfs', '/dev/mapper/vg-lv_var']),