Comment 7 for bug 995205

I've also hit the same bug. For me /etc/glance/policy.json already existed when I hit the bug.
"glance-control all start" worked for me as suggested by @DWang.

Log Snippet:
2015-09-11 15:23:17.564 DEBUG glance.common.config [-] oslo_policy.policy_default_rule = default from (pid=10238) log_opt_values /usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py:2195
2015-09-11 15:23:17.565 DEBUG glance.common.config [-] oslo_policy.policy_dirs = ['policy.d'] from (pid=10238) log_opt_values /usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py:2195
2015-09-11 15:23:17.566 DEBUG glance.common.config [-] oslo_policy.policy_file = policy.json from (pid=10238) log_opt_values /usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py:2195
2015-09-11 15:23:17.567 DEBUG glance.common.config [-] ******************************************************************************** from (pid=10238) log_opt_values /usr/local/lib/python2.7/dist-packages/oslo_config/cfg.py:2197
ERROR: Could not bind to 0.0.0.0:9191 after trying for 30 seconds
g-reg failed to start