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# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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# License for the specific language governing permissions and limitations
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# under the License.
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Volume manager manages creating, attaching, detaching, and
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destroying persistent storage volumes, ala EBS.
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Volume manager manages creating, attaching, detaching, and persistent storage.
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Persistant storage volumes keep their state independent of instances. You can
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attach to an instance, terminate the instance, spawn a new instance (even
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one from a different image) and re-attach the volume with the same data
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:volume_topic: What :mod:`rpc` topic to listen to (default: `volume`).
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:volume_manager: The module name of a class derived from
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:class:`manager.Manager` (default:
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:class:`nova.volume.manager.AOEManager`).
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:storage_availability_zone: Defaults to `nova`.
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:volume_driver: Used by :class:`AOEManager`. Defaults to
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:class:`nova.volume.driver.AOEDriver`.
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:num_shelves: Number of shelves for AoE (default: 100).
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:num_blades: Number of vblades per shelf to allocate AoE storage from
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:volume_group: Name of the group that will contain exported volumes (default:
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:aoe_eth_dev: Device name the volumes will be exported on (default: `eth0`).
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:num_shell_tries: Number of times to attempt to run AoE commands (default: 3)
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flags.DEFINE_string('storage_availability_zone',
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'availability zone of this service')
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flags.DEFINE_string('volume_driver', 'nova.volume.driver.AOEDriver',
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flags.DEFINE_string('volume_driver', 'nova.volume.driver.ISCSIDriver',
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'Driver to use for volume creation')
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flags.DEFINE_integer('num_shelves',
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'Number of vblade shelves')
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flags.DEFINE_integer('blades_per_shelf',
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'Number of vblade blades per shelf')
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class AOEManager(manager.Manager):
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"""Manages Ata-Over_Ethernet volumes"""
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flags.DEFINE_boolean('use_local_volumes', True,
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'if True, will not discover local volumes')
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class VolumeManager(manager.Manager):
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"""Manages attachable block storage devices."""
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def __init__(self, volume_driver=None, *args, **kwargs):
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"""Load the driver from the one specified in args, or from flags."""
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if not volume_driver:
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volume_driver = FLAGS.volume_driver
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self.driver = utils.import_object(volume_driver)
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super(AOEManager, self).__init__(*args, **kwargs)
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super(VolumeManager, self).__init__(*args, **kwargs)
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# NOTE(vish): Implementation specific db handling is done
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self.driver.db = self.db
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def _ensure_blades(self, context):
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"""Ensure that blades have been created in datastore"""
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total_blades = FLAGS.num_shelves * FLAGS.blades_per_shelf
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if self.db.export_device_count(context) >= total_blades:
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for shelf_id in xrange(FLAGS.num_shelves):
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for blade_id in xrange(FLAGS.blades_per_shelf):
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dev = {'shelf_id': shelf_id, 'blade_id': blade_id}
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self.db.export_device_create_safe(context, dev)
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"""Do any initialization that needs to be run if this is a
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standalone service."""
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self.driver.check_for_setup_error()
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ctxt = context.get_admin_context()
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volumes = self.db.volume_get_all_by_host(ctxt, self.host)
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logging.debug("Re-exporting %s volumes", len(volumes))
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for volume in volumes:
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self.driver.ensure_export(ctxt, volume)
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@defer.inlineCallbacks
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def create_volume(self, context, volume_id):
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"""Creates and exports the volume"""
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"""Creates and exports the volume."""
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context = context.elevated()
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logging.info("volume %s: creating", volume_id)
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volume_ref = self.db.volume_get(context, volume_id)
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logging.info("volume %s: creating", volume_ref['name'])
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self.db.volume_update(context,
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{'host': self.host})
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size = volume_ref['size']
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logging.debug("volume %s: creating lv of size %sG", volume_id, size)
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yield self.driver.create_volume(volume_ref['ec2_id'], size)
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logging.debug("volume %s: allocating shelf & blade", volume_id)
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self._ensure_blades(context)
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rval = self.db.volume_allocate_shelf_and_blade(context, volume_id)
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(shelf_id, blade_id) = rval
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logging.debug("volume %s: exporting shelf %s & blade %s", volume_id,
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yield self.driver.create_export(volume_ref['ec2_id'],
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logging.debug("volume %s: re-exporting all values", volume_id)
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yield self.driver.ensure_exports()
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# NOTE(vish): so we don't have to get volume from db again
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# before passing it to the driver.
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volume_ref['host'] = self.host
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logging.debug("volume %s: creating lv of size %sG",
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volume_ref['name'], volume_ref['size'])
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yield self.driver.create_volume(volume_ref)
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logging.debug("volume %s: creating export", volume_ref['name'])
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yield self.driver.create_export(context, volume_ref)
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now = datetime.datetime.utcnow()
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self.db.volume_update(context,
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volume_ref['id'], {'status': 'available',
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'launched_at': now})
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logging.debug("volume %s: created successfully", volume_id)
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logging.debug("volume %s: created successfully", volume_ref['name'])
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defer.returnValue(volume_id)
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@defer.inlineCallbacks
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def delete_volume(self, context, volume_id):
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"""Deletes and unexports volume"""
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"""Deletes and unexports volume."""
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context = context.elevated()
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volume_ref = self.db.volume_get(context, volume_id)
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if volume_ref['attach_status'] == "attached":
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raise exception.Error("Volume is still attached")
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if volume_ref['host'] != self.host:
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raise exception.Error("Volume is not local to this node")
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logging.debug("Deleting volume with id of: %s", volume_id)
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shelf_id, blade_id = self.db.volume_get_shelf_and_blade(context,
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yield self.driver.remove_export(volume_ref['ec2_id'],
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yield self.driver.delete_volume(volume_ref['ec2_id'])
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logging.debug("volume %s: removing export", volume_ref['name'])
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yield self.driver.remove_export(context, volume_ref)
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logging.debug("volume %s: deleting", volume_ref['name'])
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yield self.driver.delete_volume(volume_ref)
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self.db.volume_destroy(context, volume_id)
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logging.debug("volume %s: deleted successfully", volume_ref['name'])
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defer.returnValue(True)
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@defer.inlineCallbacks
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def setup_compute_volume(self, context, volume_id):
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"""Setup remote volume on compute host
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Returns path to device.
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context = context.elevated()
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volume_ref = self.db.volume_get(context, volume_id)
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yield self.driver.discover_volume(volume_ref['ec2_id'])
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shelf_id, blade_id = self.db.volume_get_shelf_and_blade(context,
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defer.returnValue("/dev/etherd/e%s.%s" % (shelf_id, blade_id))
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"""Setup remote volume on compute host.
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Returns path to device."""
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context = context.elevated()
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volume_ref = self.db.volume_get(context, volume_id)
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if volume_ref['host'] == self.host and FLAGS.use_local_volumes:
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path = yield self.driver.local_path(volume_ref)
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path = yield self.driver.discover_volume(volume_ref)
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defer.returnValue(path)
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@defer.inlineCallbacks
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def remove_compute_volume(self, context, volume_id):
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"""Remove remote volume on compute host."""
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context = context.elevated()
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volume_ref = self.db.volume_get(context, volume_id)
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if volume_ref['host'] == self.host and FLAGS.use_local_volumes:
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defer.returnValue(True)
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yield self.driver.undiscover_volume(volume_ref)
added
removed
nova/volume/manager.py
