cbworkloadgen failed to run in centos6 3.0.0-577

Install couchbase server for centos6 3.0.0-577

run cbworkloadgen, got error

[root@centos-64-x64 ~]# /opt/couchbase/bin/cbworkloadgen 10.3.4.234:8091
Traceback (most recent call last):
File "/opt/couchbase/lib/python/couchstore.py", line 26, in <module>
_lib = ctypes.CDLL(lib)
File "/usr/lib64/python2.6/ctypes/_init.py", line 353, in __init_
self._handle = _dlopen(self._name, mode)
OSError: libcouchstore-1.dll: cannot open shared object file: No such file or directory

Even in help option

[root@centos-64-x64 ~]# /opt/couchbase/bin/cbworkloadgen --help
Traceback (most recent call last):
File "/opt/couchbase/lib/python/couchstore.py", line 26, in <module>
_lib = ctypes.CDLL(lib)
File "/usr/lib64/python2.6/ctypes/_init.py", line 353, in __init_
self._handle = _dlopen(self._name, mode)
OSError: libcouchstore-1.dll: cannot open shared object file: No such file or directory

binary used couchbase-server-enterprise_centos6_x86_64_3.0.0-577-rel.rpm