Open Stack

Hi, all
   One day, it came to me that OpenStack is funny and maybe I would like to do something with it.First, I got one controller node and one compute node,then I followed the installation guides on the website. When I set up those necessary services, I began to launch instance through dashboard. After about three minutes when the "Launch" button was clicked, there came a error like this:



In compute node,there are some errors in the file /var/log/nova/nova-compute.log,some of which are:
WARNING nova.openstack.common.db.sqlalchemy.session. SQL connection failed. 10 attempts left.


ERROR oslo.messaging._drivers.common Returning exception Remote error:
ProcessExecutionError Unexpected error while running command.
Command: sudo nova-rootwrap /etc/nova/rootwrap.conf env CONFIG_FILE=["/etc/nova/nova.conf"] NETWORK_ID=2 dnsmasq --strict-order --bind-interfaces --conf-file= --pid-file=/var/lib/nova/networks/nova-br100.pid --listen-address=172.16.17.217 --except-interfaces=lo --dhcp-range=set:demo-net, 172.16.17.218,static,255.255.255.248,120s --dhcp-lease-max=8 --dhcp-hostsfile=/var/lib/nova/networks/nova-br100.conf --dhcp-script=/user/bin/nova-dhcpbridge --leasefile-ro --domain=novalocal --no-hosts --addn-hosts=/var/lib/nova/networks/nova-br100.hosts
Exit code:11


I googled that, nothing worked for me.Could you please show me where should I go?
--
Best Regards.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstack.org/pipermail/openstack/attachments/20140512/b01089cf/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 搜狗截图_2014-05-12_21-08-32.png
Type: image/png
Size: 9573 bytes
Desc: not available
URL: <http://lists.openstack.org/pipermail/openstack/attachments/20140512/b01089cf/attachment.png>