Arvados

While uploading data using command:
arv keep put <dir_name>

Following error comes up:
File "/usr/local/bin/arv-put", line 4, in <module>
main()
File "/usr/local/lib/python2.7/dist-packages/arvados/commands/put.py", line 443, in main
writer.finish_current_stream()
File "/usr/local/lib/python2.7/dist-packages/arvados/collection.py", line 401, in finish_current_stream
self.flush_data()
File "/usr/local/lib/python2.7/dist-packages/arvados/commands/put.py", line 291, in flush_data
super(ArvPutCollectionWriter, self).flush_data()
File "/usr/local/lib/python2.7/dist-packages/arvados/collection.py", line 352, in flush_data
self._my_keep().put(data_buffer[0:self.KEEP_BLOCK_SIZE]))
File "/usr/local/lib/python2.7/dist-packages/arvados/retry.py", line 157, in num_retries_setter
return orig_func(self, *args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/arvados/keep.py", line 708, in put
(data_hash, copies, thread_limiter.done()))
arvados.errors.KeepWriteError: Write fail for c2251981055c321c8449d1ab6ff14a3d: wanted 2 but wrote 0

Note: Arvados is intsalled on Ubuntu 14.04 LTS using command:
\curl -sSL http://get.arvados.org | bash