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OpenStack Study: volumeops.py**** CubicPower OpenStack Study ****
# Copyright (c) 2010 Citrix Systems, Inc. # Copyright (c) 2013 OpenStack Foundation # # Licensed under the Apache License, Version 2.0 (the "License"); you may # not use this file except in compliance with the License. You may obtain # a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations # under the License. """ Management class for Storage-related functions (attach, detach, etc). """ from nova import exception from nova.openstack.common import excutils from nova.openstack.common.gettextutils import _ from nova.openstack.common import log as logging from nova.virt.xenapi import vm_utils from nova.virt.xenapi import volume_utils LOG = logging.getLogger(__name__)
**** CubicPower OpenStack Study **** class VolumeOps(object): """Management class for Volume-related tasks."""
**** CubicPower OpenStack Study **** def __init__(self, session): self._session = session
**** CubicPower OpenStack Study **** def attach_volume(self, connection_info, instance_name, mountpoint, hotplug=True): """Attach volume storage to VM instance.""" # NOTE: No Resource Pool concept so far LOG.debug(_('Attach_volume: %(connection_info)s, %(instance_name)s,' '" %(mountpoint)s'), {'connection_info': connection_info, 'instance_name': instance_name, 'mountpoint': mountpoint}) dev_number = volume_utils.get_device_number(mountpoint) vm_ref = vm_utils.vm_ref_or_raise(self._session, instance_name) sr_uuid, vdi_uuid = self._connect_volume(connection_info, dev_number, instance_name, vm_ref, hotplug=hotplug) LOG.info(_('Mountpoint %(mountpoint)s attached to' ' instance %(instance_name)s'), {'instance_name': instance_name, 'mountpoint': mountpoint}) return (sr_uuid, vdi_uuid)
**** CubicPower OpenStack Study **** def connect_volume(self, connection_info): """Attach volume storage to the hypervisor without attaching to a VM Used to attach the just the SR - e.g. for during live migration """ # NOTE: No Resource Pool concept so far LOG.debug(_("Connect_volume: %s"), connection_info) sr_uuid, vdi_uuid = self._connect_volume(connection_info, None, None, None, False) return (sr_uuid, vdi_uuid)
**** CubicPower OpenStack Study **** def _connect_volume(self, connection_info, dev_number=None, instance_name=None, vm_ref=None, hotplug=True): driver_type = connection_info['driver_volume_type'] if driver_type not in ['iscsi', 'xensm']: raise exception.VolumeDriverNotFound(driver_type=driver_type) connection_data = connection_info['data'] sr_uuid, sr_label, sr_params = volume_utils.parse_sr_info( connection_data, 'Disk-for:%s' % instance_name) # Introduce SR if not already present sr_ref = volume_utils.find_sr_by_uuid(self._session, sr_uuid) if not sr_ref: sr_ref = volume_utils.introduce_sr( self._session, sr_uuid, sr_label, sr_params) try: # Introduce VDI if 'vdi_uuid' in connection_data: vdi_ref = volume_utils.introduce_vdi( self._session, sr_ref, vdi_uuid=connection_data['vdi_uuid']) elif 'target_lun' in connection_data: vdi_ref = volume_utils.introduce_vdi( self._session, sr_ref, target_lun=connection_data['target_lun']) else: # NOTE(sirp): This will introduce the first VDI in the SR vdi_ref = volume_utils.introduce_vdi(self._session, sr_ref) # Attach if vm_ref: vbd_ref = vm_utils.create_vbd(self._session, vm_ref, vdi_ref, dev_number, bootable=False, osvol=True) running = not vm_utils.is_vm_shutdown(self._session, vm_ref) if hotplug and running: self._session.VBD.plug(vbd_ref, vm_ref) vdi_uuid = self._session.call_xenapi("VDI.get_uuid", vdi_ref) return (sr_uuid, vdi_uuid) except Exception: with excutils.save_and_reraise_exception(): # NOTE(sirp): Forgetting the SR will have the effect of # cleaning up the VDI and VBD records, so no need to handle # that explicitly. volume_utils.forget_sr(self._session, sr_ref)
**** CubicPower OpenStack Study **** def detach_volume(self, connection_info, instance_name, mountpoint): """Detach volume storage to VM instance.""" LOG.debug(_("Detach_volume: %(instance_name)s, %(mountpoint)s"), {'instance_name': instance_name, 'mountpoint': mountpoint}) device_number = volume_utils.get_device_number(mountpoint) vm_ref = vm_utils.vm_ref_or_raise(self._session, instance_name) try: vbd_ref = vm_utils.find_vbd_by_number( self._session, vm_ref, device_number) except volume_utils.StorageError: # NOTE(sirp): If we don't find the VBD then it must have been # detached previously. LOG.warn(_('Skipping detach because VBD for %s was' ' not found'), instance_name) return # Unplug VBD if we're NOT shutdown unplug = not vm_utils.is_vm_shutdown(self._session, vm_ref) self._detach_vbd(vbd_ref, unplug, vm_ref) LOG.info(_('Mountpoint %(mountpoint)s detached from instance' ' %(instance_name)s'), {'instance_name': instance_name, 'mountpoint': mountpoint})
**** CubicPower OpenStack Study **** def _get_all_volume_vbd_refs(self, vm_ref): """Return VBD refs for all Nova/Cinder volumes.""" vbd_refs = self._session.call_xenapi("VM.get_VBDs", vm_ref) for vbd_ref in vbd_refs: other_config = self._session.call_xenapi( "VBD.get_other_config", vbd_ref) if other_config.get('osvol'): yield vbd_ref
**** CubicPower OpenStack Study **** def _detach_vbd(self, vbd_ref, unplug, vm_ref): if unplug: vm_utils.unplug_vbd(self._session, vbd_ref, vm_ref) sr_ref = volume_utils.find_sr_from_vbd(self._session, vbd_ref) vm_utils.destroy_vbd(self._session, vbd_ref) # Forget SR only if not in use volume_utils.purge_sr(self._session, sr_ref)
**** CubicPower OpenStack Study **** def detach_all(self, vm_ref): """Detach any external nova/cinder volumes and purge the SRs.""" # Generally speaking, detach_all will be called with VM already # shutdown; however if it's still running, we can still perform the # operation by unplugging the VBD first. unplug = not vm_utils.is_vm_shutdown(self._session, vm_ref) vbd_refs = self._get_all_volume_vbd_refs(vm_ref) for vbd_ref in vbd_refs: self._detach_vbd(vbd_ref, unplug, vm_ref)
**** CubicPower OpenStack Study **** def find_bad_volumes(self, vm_ref): """Find any volumes with their connection severed. Certain VM operations (e.g. `VM.start`, `VM.reboot`, etc.) will not work when a VBD is present that points to a non-working volume. To work around this, we scan for non-working volumes and detach them before retrying a failed operation. """ bad_devices = [] vbd_refs = self._get_all_volume_vbd_refs(vm_ref) for vbd_ref in vbd_refs: sr_ref = volume_utils.find_sr_from_vbd(self._session, vbd_ref) try: # TODO(sirp): bug1152401 This relies on a 120 sec timeout # within XenServer, update this to fail-fast when this is fixed # upstream self._session.call_xenapi("SR.scan", sr_ref) except self._session.XenAPI.Failure as exc: if exc.details[0] == 'SR_BACKEND_FAILURE_40': vbd_rec = vbd_rec = self._session.call_xenapi( "VBD.get_record", vbd_ref) bad_devices.append('/dev/%s' % vbd_rec['device']) else: raise return bad_devices
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