While trying to install OpenStack icehouse, faced an issue with nova-api service.It was not getting started. The following error was coming up in the Nova-api log Command: sudo nova-rootwrap /etc/nova/rootwrap.conf iptables-save -c Exit code: 1 ....... nova Stdout: '' 2014-10-17 07:21:08.058 27270 TRACE nova Stderr: 'Traceback (most recent call last):\n File "/usr/bin/nova-rootwrap", line 6, in <module>\n from oslo.rootwrap.cmd import main\nImportError: No module named rootwrap.cmd\n' Problem was with one of the oslo.rootwrap module. It was broken Solution is to upgrade the module using pip #pip install oslo.rootwrap --upgrade