[root@controller ~]# nova flavor-show 100
+----------------------------+--------+
| Property                   | Value  |
+----------------------------+--------+
| name                       | jitest |
| ram                        | 512    |
| OS-FLV-DISABLED:disabled   | False  |
| vcpus                      | 2      |
| extra_specs                | {}     |
| swap                       |        |
| os-flavor-access:is_public | True   |
| rxtx_factor                | 2.0    |
| OS-FLV-EXT-DATA:ephemeral  | 0      |
| disk                       | 2      |
| id                         | 100    |
+----------------------------+--------+
[root@controller ~]# nova flavor-show 12
+----------------------------+----------+
| Property                   | Value    |
+----------------------------+----------+
| name                       | m2.test1 |
| ram                        | 512      |
| OS-FLV-DISABLED:disabled   | False    |
| vcpus                      | 2        |
| extra_specs                | {}       |
| swap                       |          |
| os-flavor-access:is_public | True     |
| rxtx_factor                | 1.0      |
| OS-FLV-EXT-DATA:ephemeral  | 0        |
| disk                       | 1        |
| id                         | 12       |
+----------------------------+----------+



[root@controller ~]# nova show 959567d4-3ad3-4773-8d58-f95089e604fd
+--------------------------------------+------------------------------------------------------------+
| Property                             | Value                                                      
| flavor                               | m2.test1 (12) 


[root@controller ~]# nova resize --poll 959567d4-3ad3-4773-8d58-f95089e604fd 100
Instance resizing... 100% complete
Finished


after this operation

[root@controller ~]# nova show 959567d4-3ad3-4773-8d58-f95089e604fd
+--------------------------------------+------------------------------------------------------------+
| Property                             | Value                                                      |
+--------------------------------------+------------------------------------------------------------+
| status                               | ACTIVE                                                     
| flavor                               | m2.test1 (12)   


conductor.log has following info:

2014-03-26 06:27:47.196 24972 WARNING nova.scheduler.utils [req-d71f5543-51aa-422e-80cc-24b82d654c54 d6779a827003465db2d3c52fe135d926 45210fba73d24dd681dc5c292c6b1e7f] [instance: a9dd1fd6-27fb-4128-92e6-93bcab085a98] Setting instance to ACTIVE state.
2014-03-26 06:27:47.389 24972 WARNING nova.conductor.manager [req-d71f5543-51aa-422e-80cc-24b82d654c54 d6779a827003465db2d3c52fe135d926 45210fba73d24dd681dc5c292c6b1e7f] No valid host found for cold migrate
2014-03-26 06:28:53.739 24972 WARNING nova.scheduler.utils [req-d0d32b3d-c863-4850-9980-c520ab85f8f5 d6779a827003465db2d3c52fe135d926 45210fba73d24dd681dc5c292c6b1e7f] Failed to compute_task_migrate_server: No valid host was found.
Traceback (most recent call last):

  File "/usr/lib/python2.6/site-packages/nova/openstack/common/rpc/common.py", line 420, in catch_client_exception
    return func(*args, **kwargs)

  File "/usr/lib/python2.6/site-packages/nova/scheduler/manager.py", line 298, in select_destinations
    filter_properties)

  File "/usr/lib/python2.6/site-packages/nova/scheduler/filter_scheduler.py", line 147, in select_destinations
    raise exception.NoValidHost(reason='')

NoValidHost: No valid host was found.

2014-03-26 06:28:53.740 24972 WARNING nova.scheduler.utils [req-d0d32b3d-c863-4850-9980-c520ab85f8f5 d6779a827003465db2d3c52fe135d926 45210fba73d24dd681dc5c292c6b1e7f] [instance: 959567d4-3ad3-4773-8d58-f95089e604fd] Setting instance to ACTIVE state.
2014-03-26 06:28:53.896 24972 WARNING nova.conductor.manager [req-d0d32b3d-c863-4850-9980-c520ab85f8f5 d6779a827003465db2d3c52fe135d926 45210fba73d24dd681dc5c292c6b1e7f] No valid host found for cold migrate