openstack/nova-powervm
Code Issues Proposed changes

Provide minimum VIOS connection on vSCSI volumes

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When the admin attempts to connect a volume, they may wish to specify a
minimum level of redundancy (how many Virtual I/O Servers it connects
to).  This change set provides the operator with the ability to set a
minimum number of VIOSes.

Change-Id: Id4d4ca945190f04436792cac12fa08f4412bc114
Closes-Bug: 1504037
This commit is contained in:
Drew Thorstensen 2015-10-08 15:08:06 -04:00
parent f7de66aac0
commit 4ce1db1143
4 changed files with 77 additions and 12 deletions
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4
doc/source/devref/usage.rst
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@ -118,6 +118,10 @@ Volume Options
| | Cinder volumes should be attached to the Virtual Machine. |
| | The options are: npiv or vscsi. |
+--------------------------------------+------------------------------------------------------------+
| vscsi_vios_connections_required = 1 | (IntOpt) Indicates a minimum number of Virtual I/O Servers |
| | that are required to support a Cinder volume attach with |
| | the vSCSI volume connector. |
+--------------------------------------+------------------------------------------------------------+
| ports_per_fabric = 1 | (IntOpt) (NPIV only) The number of physical ports that |
| | should be connected directly to the Virtual Machine, per |
| | fabric. |

37
nova_powervm/tests/virt/powervm/volume/test_vscsi.py
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@ -146,8 +146,11 @@ class TestVSCSIAdapter(BaseVSCSITest):
@mock.patch('pypowervm.tasks.scsi_mapper.add_map')
@mock.patch('pypowervm.tasks.scsi_mapper.build_vscsi_mapping')
@mock.patch('pypowervm.tasks.hdisk.discover_hdisk')
def test_connect_volume_no_update(self, mock_disc_hdisk, mock_build_map,
mock_add_map):
@mock.patch('nova_powervm.virt.powervm.volume.vscsi.VscsiVolumeAdapter.'
'_validate_vios_on_connection')
def test_connect_volume_no_update(
self, mock_validate_vioses, mock_disc_hdisk, mock_build_map,
mock_add_map):
"""Make sure we don't do an actual update of the VIOS if not needed."""
# The mock return values
mock_build_map.return_value = 'fake_map'
@ -159,6 +162,7 @@ class TestVSCSIAdapter(BaseVSCSITest):
self.vol_drv.connect_volume()
# As initialized above, remove_maps returns True to trigger update.
mock_validate_vioses.assert_called_with(1)
self.assertEqual(1, mock_add_map.call_count)
self.assertEqual(0, self.ft_fx.patchers['update'].mock.call_count)
self.assertEqual(1, mock_disc_hdisk.call_count)
@ -166,8 +170,11 @@ class TestVSCSIAdapter(BaseVSCSITest):
@mock.patch('pypowervm.tasks.hdisk.build_itls')
@mock.patch('pypowervm.tasks.hdisk.lua_recovery')
@mock.patch('pypowervm.tasks.scsi_mapper.add_vscsi_mapping')
def test_connect_volume_to_initiatiors(self, mock_add_vscsi_mapping,
mock_lua_recovery, mock_build_itls):
@mock.patch('nova_powervm.virt.powervm.volume.vscsi.VscsiVolumeAdapter.'
'_validate_vios_on_connection')
def test_connect_volume_to_initiatiors(
self, mock_validate_vioses, mock_add_vscsi_mapping, mock_lua_recovery,
mock_build_itls):
"""Tests that the connect w/out initiators throws errors."""
mock_lua_recovery.return_value = (
hdisk.LUAStatus.DEVICE_AVAILABLE, 'devname', 'udid')
@ -175,10 +182,32 @@ class TestVSCSIAdapter(BaseVSCSITest):
mock_instance = mock.Mock()
mock_instance.system_metadata = {}
mock_validate_vioses.side_effect = p_exc.VolumeAttachFailed(
volume_id='1', reason='message', instance_name='inst')
mock_build_itls.return_value = []
self.assertRaises(p_exc.VolumeAttachFailed,
self.vol_drv.connect_volume)
# Validate that the validate was called with no vioses.
mock_validate_vioses.assert_called_with(0)
def test_validate_vios_on_connection(self):
# Happy path!
self.vol_drv._validate_vios_on_connection(1)
# Raise if no VIOSes are found
self.assertRaises(p_exc.VolumeAttachFailed,
self.vol_drv._validate_vios_on_connection, 0)
# Multi VIOS required happy path.
self.flags(vscsi_vios_connections_required=2, group='powervm')
self.vol_drv._validate_vios_on_connection(2)
# Raise if multiple VIOSes required
self.assertRaises(p_exc.VolumeAttachFailed,
self.vol_drv._validate_vios_on_connection, 1)
@mock.patch('pypowervm.tasks.hdisk.remove_hdisk')
@mock.patch('pypowervm.wrappers.virtual_io_server.VIOS.hdisk_from_uuid')
@mock.patch('pypowervm.tasks.scsi_mapper.remove_maps')

6
nova_powervm/virt/powervm/volume/__init__.py
View File

@ -34,7 +34,11 @@ vol_adapter_opts = [
default='nova_powervm.virt.powervm.volume.vscsi.'
'VscsiVolumeAdapter',
help='Volume Adapter API to connect FC volumes through Virtual '
'I/O Server using PowerVM vSCSI connection mechanism')
'I/O Server using PowerVM vSCSI connection mechanism'),
cfg.IntOpt('vscsi_vios_connections_required', default=1,
help='Indicates a minimum number of Virtual I/O Servers that '
'are required to support a Cinder volume attach with the '
'vSCSI volume connector.')
]
CONF.register_opts(vol_adapter_opts, group='powervm')

42
nova_powervm/virt/powervm/volume/vscsi.py
View File

@ -200,16 +200,44 @@ class VscsiVolumeAdapter(v_driver.FibreChannelVolumeAdapter):
connect_volume_to_vio, provides='vio_modified', flag_update=False)
ret = connect_ftsk.execute()
# If no valid hdisk was found, log and exit
if not any([result['vio_modified']
for result in ret['wrapper_task_rets'].values()]):
# Check the number of VIOSes
vioses_modified = 0
for result in ret['wrapper_task_rets'].values():
if result['vio_modified']:
vioses_modified += 1
self._validate_vios_on_connection(vioses_modified)
def _validate_vios_on_connection(self, num_vioses_found):
"""Validates that the correct number of VIOSes were discovered.
Certain environments may have redundancy requirements. For PowerVM
this is achieved by having multiple Virtual I/O Servers. This method
will check to ensure that the operator's requirements for redundancy
have been met. If not, a specific error message will be raised.
:param num_vioses_found: The number of VIOSes the hdisk was found on.
"""
# Is valid as long as the vios count exceeds the conf value.
if num_vioses_found >= CONF.powervm.vscsi_vios_connections_required:
return
# Should have a custom message based on zero or 'some but not enough'
# I/O Servers.
if num_vioses_found == 0:
msg = (_('Failed to discover valid hdisk on any Virtual I/O '
'Server for volume %(volume_id)s.') %
{'volume_id': self.volume_id})
LOG.error(msg)
ex_args = {'volume_id': self.volume_id, 'reason': msg,
'instance_name': self.instance.name}
raise p_exc.VolumeAttachFailed(**ex_args)
else:
msg = (_('Failed to discover the hdisk on the required number of '
'Virtual I/O Servers. Volume %(volume_id)s required '
'%(vios_req)d Virtual I/O Servers, but the disk was only '
'found on %(vios_act)d Virtual I/O Servers.') %
{'volume_id': self.volume_id, 'vios_act': num_vioses_found,
'vios_req': CONF.powervm.vscsi_vios_connections_required})
LOG.error(msg)
ex_args = {'volume_id': self.volume_id, 'reason': msg,
'instance_name': self.instance.name}
raise p_exc.VolumeAttachFailed(**ex_args)
def _disconnect_volume(self):
"""Disconnect the volume."""