When resizing a volume, cinder will notify nova that a volume has changed its size. For iSCSI attached volumes (ie: Dell Unity), the package lsscsi is required for that to work. Without it, you get this error: 2021-08-10 09:44:02.400 1816368 INFO os_brick.initiator.connectors.iscsi [req-98b38968-a179-4a3c-bf09-dfe5dcee9b66 aa291ad6c5b4430d9a5e268850c5aed8 ff58079dba31444da859ff6f91a2f983 - 83859026773d453ca315c30285f94efa 83859026773d453ca315c30285f94efa] Found paths for volume ['/dev/disk/by-path/ip-10.123.110.4:3260-iscsi-iqn.1992-04.com.emc:cx.ckm01211605212.a4-lun-86', '/dev/disk/by-path/ip-10.123.120.4:3260-iscsi-iqn.1992-04.com.emc:cx.ckm01211605212.b4-lun-86', '/dev/disk/by-path/ip-10.123.120.5:3260-iscsi-iqn.1992-04.com.emc:cx.ckm01211605212.b5-lun-86', '/dev/disk/by-path/ip-10.123.110.5:3260-iscsi-iqn.1992-04.com.emc:cx.ckm01211605212.a5-lun-86'] 2021-08-10 09:44:02.424 1816368 WARNING nova.compute.manager [req-98b38968-a179-4a3c-bf09-dfe5dcee9b66 aa291ad6c5b4430d9a5e268850c5aed8 ff58079dba31444da859ff6f91a2f983 - 83859026773d453ca315c30285f94efa 83859026773d453ca315c30285f94efa] [instance: 6cf7a8c6-255f-4b69-812a-39dc0fa279b6] Extend volume failed, volume_id=ac43884b-916c-44b9-be46-393325ad64cc, reason: [Errno 2] No such file or directory: 'lsscsi' Command: lsscsi Exit code: - Stdout: None Stderr: None: oslo_concurrency.processutils.ProcessExecutionError: [Errno 2] No such file or directory: 'lsscsi' 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server [req-98b38968-a179-4a3c-bf09-dfe5dcee9b66 aa291ad6c5b4430d9a5e268850c5aed8 ff58079dba31444da859ff6f91a2f983 - 83859026773d453ca315c30285f94efa 83859026773d453ca315c30285f94efa] Exception during message handling: oslo_concurrency.processutils.ProcessExecutionError: [Errno 2] No such file or directory: 'lsscsi' Command: lsscsi Exit code: - Stdout: None Stderr: None 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Traceback (most recent call last): 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/privileged/rootwrap.py", line 171, in execute 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return custom_execute(*cmd, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/privileged/rootwrap.py", line 142, in custom_execute 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return putils.execute(on_execute=on_execute, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_concurrency/processutils.py", line 388, in execute 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server obj = subprocess.Popen(cmd, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/eventlet/green/subprocess.py", line 58, in __init__ 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server subprocess_orig.Popen.__init__(self, args, 0, *argss, **kwds) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3.8/subprocess.py", line 858, in __init__ 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server self._execute_child(args, executable, preexec_fn, close_fds, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3.8/subprocess.py", line 1704, in _execute_child 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server raise child_exception_type(errno_num, err_msg, err_filename) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server FileNotFoundError: [Errno 2] No such file or directory: 'lsscsi' 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server During handling of the above exception, another exception occurred: 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Traceback (most recent call last): 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/server.py", line 165, in _process_incoming 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 309, in dispatch 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 229, in _do_dispatch 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/exception_wrapper.py", line 76, in wrapped 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server _emit_exception_notification( 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__ 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server self.force_reraise() 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server six.reraise(self.type_, self.value, self.tb) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/six.py", line 703, in reraise 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server raise value 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/exception_wrapper.py", line 69, in wrapped 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return f(self, context, *args, **kw) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 10405, in external_instance_event 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server self.extend_volume(context, instance, event.tag) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/compute/utils.py", line 1434, in decorated_function 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return function(self, context, *args, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 216, in decorated_function 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server compute_utils.add_instance_fault_from_exc(context, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__ 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server self.force_reraise() 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server six.reraise(self.type_, self.value, self.tb) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/six.py", line 703, in reraise 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server raise value 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 205, in decorated_function 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return function(self, context, *args, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 10262, in extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server self.driver.extend_volume(context, connection_info, instance, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/virt/libvirt/driver.py", line 2199, in extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server new_size = self._extend_volume(connection_info, instance, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/virt/libvirt/driver.py", line 1743, in _extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return vol_driver.extend_volume(connection_info, instance, 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/nova/virt/libvirt/volume/iscsi.py", line 86, in extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server new_size = self.connector.extend_volume(connection_info['data']) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/utils.py", line 144, in trace_logging_wrapper 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return f(*args, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/oslo_concurrency/lockutils.py", line 360, in inner 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return f(*args, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/initiator/connectors/iscsi.py", line 477, in extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server return self._linuxscsi.extend_volume( 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/initiator/linuxscsi.py", line 581, in extend_volume 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server device = self.get_device_info(volume_path) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/initiator/linuxscsi.py", line 114, in get_device_info 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server (out, _err) = self._execute('lsscsi') 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/executor.py", line 52, in _execute 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server result = self.__execute(*args, **kwargs) 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server File "/usr/lib/python3/dist-packages/os_brick/privileged/rootwrap.py", line 186, in execute 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server raise putils.ProcessExecutionError( 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server oslo_concurrency.processutils.ProcessExecutionError: [Errno 2] No such file or directory: 'lsscsi' 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Command: lsscsi 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Exit code: - 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Stdout: None 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Stderr: None 2021-08-10 09:44:02.497 1816368 ERROR oslo_messaging.rpc.server Running: sudo apt install lsscsi on the compute node fixes this issue.