We are using Cinder on Ubuntu 14.04 working with NFS server, now we are facing error when we tried to extend the Cinder volume:

2014-09-11 15:51:28.883 10261 INFO cinder.volume.manager [req-66b104d6-56e4-4130-8bc6-2683dfa51a66 c4c93d945b2e449db7fe2a2328f21d8b 5f42cedeae954d658501b591252be8bc - - -] volume ef890b11-a8ea-4bc7-a6d2-949bd1bfbf16: extending 2014-09-11 15:51:28.884 10261 ERROR cinder.volume.manager [req-66b104d6-56e4-4130-8bc6-2683dfa51a66 c4c93d945b2e449db7fe2a2328f21d8b 5f42cedeae954d658501b591252be8bc - - -] volume ef890b11-a8ea-4bc7-a6d2-949bd1bfbf16: Error trying to extend volume 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager Traceback (most recent call last): 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager File "/usr/lib/python2.7/dist-packages/cinder/volume/manager.py", line 1169, in extend_volume 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager self.driver.extend_volume(volume, new_size) 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager File "/usr/lib/python2.7/dist-packages/cinder/volume/driver.py", line 530, in extend_volume 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager raise NotImplementedError(msg) 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager NotImplementedError: Extend volume not implemented 2014-09-11 15:51:28.884 10261 TRACE cinder.volume.manager