how to find OpenStack Nova version

root@saju-M61PME-S2P:~# nova-manage shell python
Python 2.7.1+ (r271:86832, Apr 11 2011, 18:05:24)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>>
>>> from nova import version
>>> version.version_string()
'2011.2'
>>> version.version_string_with_vcs()
u'2011.2-workspace:tarmac-20110415024701-a9bdb77vaatk99lh'
>>>