I did more debug: 1) the nova schduler did choose another compute host as destination , and instance's host was changed into the destination when the instance is in VERIFY_RESIZE state. But from vCenter the instance was still in original EXSi host (actuall there are two instances ,one with old name , one with suffix _orig). This is not right. 2) after resize , instance's host name was changed, the changed host name is not mananged by nova-compute , then resize confrim, nova-compute can't find the changed host name , then the error was raised. Before resize [root@10-1-0-71 nova]# nova show gcb_resize1 +--------------------------------------+----------------------------------------------------------+ | Property | Value | +--------------------------------------+----------------------------------------------------------+ | status | ACTIVE | | updated | 2013-12-18T07:42:27Z | | OS-EXT-STS:task_state | None | | OS-EXT-SRV-ATTR:host | vmware_nova_cluster01 | | key_name | None | | image | trend-thin (4432ca56-8be0-4794-9c22-52a8c7a2bf55) | | network1 network | 10.0.1.2 | | hostId | 964f8e94c6b9084b0059044896687b96e12dd97a33d61deb564244ee | | OS-EXT-STS:vm_state | active | | OS-EXT-SRV-ATTR:instance_name | instance-000000ca | | OS-SRV-USG:launched_at | 2013-12-18T07:42:27.000000 | | OS-EXT-SRV-ATTR:hypervisor_hostname | domain-c17(cluster01) | | flavor | m1.tiny (1) | | id | 2f93a76e-fcd7-4fe2-96c6-1a750b430f3c | | security_groups | [{u'name': u'default'}] | | OS-SRV-USG:terminated_at | None | | user_id | 01dd320eb49d4bdfaa08a9ec021a48d4 | | name | gcb_resize1 | | created | 2013-12-18T07:41:38Z | | tenant_id | 045dd87f67eb40d1b18f6c9498be3bd9 | | OS-DCF:diskConfig | MANUAL | | metadata | {} | | os-extended-volumes:volumes_attached | [] | | accessIPv4 | | | accessIPv6 | | | progress | 0 | | OS-EXT-STS:power_state | 1 | | OS-EXT-AZ:availability_zone | nova | | config_drive | | +--------------------------------------+----------------------------------------------------------+ After resize: [root@10-1-0-71 nova]# nova show gcb_resize1 +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------+ | Property | Value | +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------+ | status | ERROR | | updated | 2013-12-18T08:05:52Z | | OS-EXT-STS:task_state | None | | OS-EXT-SRV-ATTR:host | vmware_nova_cluster02 | | key_name | None | | image | trend-thin (4432ca56-8be0-4794-9c22-52a8c7a2bf55) | | network1 network | 10.0.1.2 | | hostId | 5f93f60c197ee7af029b96f22fb39dea07a9caae6cbaee77481a6919 | | OS-EXT-STS:vm_state | error | | OS-EXT-SRV-ATTR:instance_name | instance-000000ca | | OS-SRV-USG:launched_at | 2013-12-18T07:59:12.000000 | | OS-EXT-SRV-ATTR:hypervisor_hostname | domain-c382(cluster02) | | flavor | m1.small (2) | | id | 2f93a76e-fcd7-4fe2-96c6-1a750b430f3c | | security_groups | [{u'name': u'default'}] | | OS-SRV-USG:terminated_at | None | | user_id | 01dd320eb49d4bdfaa08a9ec021a48d4 | | name | gcb_resize1 | | created | 2013-12-18T07:41:38Z | | tenant_id | 045dd87f67eb40d1b18f6c9498be3bd9 | | OS-DCF:diskConfig | MANUAL | | metadata | {} | | os-extended-volumes:volumes_attached | [] | | accessIPv4 | | | accessIPv6 | | | fault | {u'message': u'NV-3AB798A The resource domain-c382(cluster02) does not exist', u'code': 404, u'created': u'2013-12-18T08:05:52Z'} | | OS-EXT-STS:power_state | 1 | | OS-EXT-AZ:availability_zone | nova | | config_drive | | +--------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------+