If a Lefthand volume is attached to an instance, and a live migration is attempted on that instance, Cinder will throw errors.
2014-04-22 14:23:32.876 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Got file lock "lefthand" at /opt/stack/data/cinder/cinder-lefthand for method "initialize_connection"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:232
2014-04-22 14:23:32.912 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Released file lock "lefthand" at /opt/stack/data/cinder/cinder-lefthand for method "initialize_connection"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:239
2014-04-22 14:23:32.913 ERROR cinder.volume.manager [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Unable to fetch connection information from backend: Error (HTTP 500) OPERATION_FAILED - The operation failed: The association for the volume list group cannot be added because the volume list group 'cld5b15VolumeList1398189674' already exists on volume 'volume-cadbc12b-8f77-4496-afa6-94630f223557'.
2014-04-22 14:23:32.913 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Got semaphore "lefthand" for method "remove_export"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:191
2014-04-22 14:23:32.914 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Attempting to grab file lock "lefthand" for method "remove_export"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:202
2014-04-22 14:23:32.914 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Got file lock "lefthand" at /opt/stack/data/cinder/cinder-lefthand for method "remove_export"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:232
2014-04-22 14:23:32.915 DEBUG cinder.openstack.common.lockutils [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Released file lock "lefthand" at /opt/stack/data/cinder/cinder-lefthand for method "remove_export"... from (pid=57883) inner /opt/stack/cinder/cinder/openstack/common/lockutils.py:239
2014-04-22 14:23:32.915 ERROR oslo.messaging.rpc.dispatcher [req-ec047dcb-f3da-42ab-9ae4-3739155cf445 0ae03dba92094cfaabe9c0d6e5f359d9 4650989f8e1841b28f6123b66660e848] Exception during message handling: Bad or unexpected response from the storage volume backend API: Unable to fetch connection information from backend: Error (HTTP 500) OPERATION_FAILED - The operation failed: The association for the volume list group cannot be added because the volume list group 'cld5b15VolumeList1398189674' already exists on volume 'volume-cadbc12b-8f77-4496-afa6-94630f223557'.
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher Traceback (most recent call last):
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 133, in _dispatch_and_reply
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher incoming.message))
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 176, in _dispatch
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher return self._do_dispatch(endpoint, method, ctxt, args)
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 122, in _do_dispatch
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher result = getattr(endpoint, method)(ctxt, **new_args)
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher File "/opt/stack/cinder/cinder/volume/manager.py", line 804, in initialize_connection
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher raise exception.VolumeBackendAPIException(data=err_msg)
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher VolumeBackendAPIException: Bad or unexpected response from the storage volume backend API: Unable to fetch connection information from backend: Error (HTTP 500) OPERATION_FAILED - The operation failed: The association for the volume list group cannot be added because the volume list group 'cld5b15VolumeList1398189674' already exists on volume 'volume-cadbc12b-8f77-4496-afa6-94630f223557'.
2014-04-22 14:23:32.915 TRACE oslo.messaging.rpc.dispatcher
Fix proposed to branch: master /review. openstack. org/112692
Review: https:/