openstack
/
nova
Code Issues Proposed changes

libvirt: Calculate disk_over_committed for raw instances 

During update_available_resource periodic task, nova-compute reports total
amount of disk_over_committed in order to determine current hypervisor's
available_disk_least.

Currently, disk_over_committed is set to 0 for raw instances, which is
appropriate when [compute]/preallocate_images option is set to space as images
are fully allocated and because file size is equal to allocated size.
If not set, the raw disk file is sparsely allocated and
over_committed_disk_size have to be calculated in order to not mislead
available_disk_least value.

This change introduces over_committed_disk_size calucation also for raw disk.

Closes-Bug: #1870357

Change-Id: I9788ab12f5cfe0b1884f265482ceb9f533e9574e
This commit is contained in:
Alexandre Arents 2020-04-01 15:44:18 +00:00
parent 874c2fe329
commit addd6cadda
2 changed files with 35 additions and 6 deletions
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39
nova/tests/unit/virt/libvirt/test_driver.py
View File

@ -16407,10 +16407,10 @@ class LibvirtConnTestCase(test.NoDBTestCase,
'over_committed_disk_size': '10653532160'}],
'instance0000002':
[{'type': 'raw', 'path': '/somepath/disk2',
'virt_disk_size': '0',
'backing_file': '/somepath/disk2',
'disk_size': '10737418240',
'over_committed_disk_size': '0'}]}
'virt_disk_size': '10737418240',
'backing_file': '',
'disk_size': '5350000000',
'over_committed_disk_size': '5387418240'}]}
def get_info(cfg, block_device_info):
return fake_disks.get(cfg.name)
@ -16430,7 +16430,7 @@ class LibvirtConnTestCase(test.NoDBTestCase,
mock_info.side_effect = get_info
result = drvr._get_disk_over_committed_size_total()
self.assertEqual(result, 10653532160)
self.assertEqual(result, 16040950400)
mock_list.assert_called_once_with(only_running=False)
self.assertEqual(2, mock_info.call_count)
@ -16649,6 +16649,35 @@ class LibvirtConnTestCase(test.NoDBTestCase,
self.assertEqual(disk_info[0]['disk_size'],
disk_info[0]['virt_disk_size'])
@mock.patch('os.stat')
@mock.patch('os.path.getsize')
def test_get_instance_disk_info_from_config_raw_files(self,
mock_getsize, mock_stat):
"""Test that over_committed_disk_size are calculated also for raw
images_type, since disk can be sparsely allocated if
[compute]/preallocate_images option is not set to space.
"""
config = vconfig.LibvirtConfigGuest()
disk_config = vconfig.LibvirtConfigGuestDisk()
disk_config.source_type = "file"
disk_config.source_path = "fake"
disk_config.driver_format = "raw"
config.devices.append(disk_config)
disk_virtual_size = 53687091200
disk_actual_size = 3687091200
disk_actual_size_blocks = disk_actual_size / 512
expected_over_committed_disk_size = disk_virtual_size -\
disk_actual_size
mock_getsize.return_value = disk_virtual_size
mock_stat.return_value = mock.Mock(st_blocks=disk_actual_size_blocks)
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
disk_info = drvr._get_instance_disk_info_from_config(config, None)
self.assertEqual(expected_over_committed_disk_size,
disk_info[0]['over_committed_disk_size'])
def test_cpu_info(self):
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), True)

2
nova/virt/libvirt/driver.py
View File

@ -9604,7 +9604,7 @@ class LibvirtDriver(driver.ComputeDriver):
dk_size = os.stat(path).st_blocks * 512
virt_size = os.path.getsize(path)
backing_file = ""
over_commit_size = 0
over_commit_size = int(virt_size) - dk_size
elif disk_type == 'block' and block_device_info:
dk_size = lvm.get_volume_size(path)