*** This bug is a duplicate of bug 1867075 *** https://bugs.launchpad.net/bugs/1867075
** This bug has been marked a duplicate of bug 1867075 Arm64: Instance with Configure Drive attach volume failed failed -- You received this bug notification because you are a member of Yahoo! Engineering Team, which is subscribed to OpenStack Compute (nova). https://bugs.launchpad.net/bugs/1801342 Title: Attach a volume with scsi bus on an instance boot from cdrom fails Status in OpenStack Compute (nova): In Progress Bug description: Following the upstream documentation to create images from an ISO (https://docs.openstack.org/nova/rocky/user/launch-instance-using-ISO- image.html) with an image from a vendor that required to have the disk attached on the scsi bus (/dev/sda) in order to install the system, it failed on attach volume step with the following traceback: Driver failed to attach volume 95b42945-5d2a-4fba-b970-1d3fafcfbecc at /dev/sda: ValueError: max() arg is an empty sequence Traceback (most recent call last): File "/usr/lib/python2.7/site-packages/nova/virt/block_device.py", line 538, in _volume_attach device_type=self['device_type'], encryption=encryption) File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 1451, in attach_volume disk_info['unit'] = self._get_scsi_controller_max_unit(guest) + 1 File "/usr/lib/python2.7/site-packages/nova/virt/libvirt/driver.py", line 1134, in _get_scsi_controller_max_unit return max(ret) ValueError: max() arg is an empty sequence Looking at the code def _get_scsi_controller_max_unit(self, guest): """Returns the max disk unit used by scsi controller""" xml = guest.get_xml_desc() tree = etree.fromstring(xml) addrs = "./devices/disk[@device='disk']/address[@type='drive']" ret = [] for obj in tree.findall(addrs): ret.append(int(obj.get('unit', 0))) return max(ret) As the instance has no existing devices in the scsi device bus, then the ret array is empty and the max function just fails with the traceback mentioned above. To manage notifications about this bug go to: https://bugs.launchpad.net/nova/+bug/1801342/+subscriptions -- Mailing list: https://launchpad.net/~yahoo-eng-team Post to : yahoo-eng-team@lists.launchpad.net Unsubscribe : https://launchpad.net/~yahoo-eng-team More help : https://help.launchpad.net/ListHelp