If your goal is to split your VM load across more than one server, you can connect an additional nova-compute node to a cloud controller node. This configuring can be reproduced on multiple compute servers to start building a true multi-node OpenStack Compute cluster. To build out and scale the Compute platform, you spread out services amongst many servers. While there are additional ways to accomplish the build-out, this section describes adding compute nodes, and the service we are scaling out is called 'nova-compute.' For a multi-node install you only make changes to nova.conf and copy it to additional compute nodes. Ensure each nova.conf file points to the correct IP addresses for the respective services. Customize the nova.conf example below to match your environment. The CC_ADDR is the Cloud Controller IP Address. --dhcpbridge_flagfile=/etc/nova/nova.conf --dhcpbridge=/usr/bin/nova-dhcpbridge --flat_network_bridge=br100 --logdir=/var/log/nova --state_path=/var/lib/nova --verbose --sql_connection=mysql://root:nova@CC_ADDR/nova --s3_host=CC_ADDR --rabbit_host=CC_ADDR --ec2_api=CC_ADDR --ec2_url=http://CC_ADDR:8773/services/Cloud --network_manager=nova.network.manager.FlatManager --fixed_range= network/CIDR --network_size=number of addresses By default, Nova sets the bridge device based on the setting in --flat_network_bridge. Now you can edit /etc/network/interfaces with the following template, updated with your IP information. # The loopback network interface auto lo iface lo inet loopback # The primary network interface auto br100 iface br100 inet static bridge_ports eth0 bridge_stp off bridge_maxwait 0 bridge_fd 0 address xxx.xxx.xxx.xxx netmask xxx.xxx.xxx.xxx network xxx.xxx.xxx.xxx broadcast xxx.xxx.xxx.xxx gateway xxx.xxx.xxx.xxx # dns-* options are implemented by the resolvconf package, if installed dns-nameservers xxx.xxx.xxx.xxx Restart networking: /etc/init.d/networking restart With nova.conf updated and networking set, configuration is nearly complete. First, bounce the relevant services to take the latest updates: restart libvirt-bin; service nova-compute restart To avoid issues with KVM and permissions with Nova, run the following commands to ensure we have VM's that are running optimally: chgrp kvm /dev/kvm chmod g+rwx /dev/kvm If you want to use the 10.04 Ubuntu Enterprise Cloud images that are readily available at http://uec-images.ubuntu.com/releases/10.04/release/, you may run into delays with booting. Any server that does not have nova-api running on it needs this iptables entry so that UEC images can get metadata info. On compute nodes, configure the iptables with this next step: iptables -t nat -A PREROUTING -d 169.254.169.254/32 -p tcp -m tcp --dport 80 -j DNAT --to-destination $NOVA_API_IP:8773 Lastly, confirm that your compute node is talking to your cloud controller. From the cloud controller, run this database query: mysql -u$MYSQL_USER -p$MYSQL_PASS nova -e 'select * from services;' In return, you should see something similar to this: +---------------------+---------------------+------------+---------+----+----------+----------------+-----------+--------------+----------+-------------------+ | created_at | updated_at | deleted_at | deleted | id | host | binary | topic | report_count | disabled | availability_zone | +---------------------+---------------------+------------+---------+----+----------+----------------+-----------+--------------+----------+-------------------+ | 2011-01-28 22:52:46 | 2011-02-03 06:55:48 | NULL | 0 | 1 | osdemo02 | nova-network | network | 46064 | 0 | nova | | 2011-01-28 22:52:48 | 2011-02-03 06:55:57 | NULL | 0 | 2 | osdemo02 | nova-compute | compute | 46056 | 0 | nova | | 2011-01-28 22:52:52 | 2011-02-03 06:55:50 | NULL | 0 | 3 | osdemo02 | nova-scheduler | scheduler | 46065 | 0 | nova | | 2011-01-29 23:49:29 | 2011-02-03 06:54:26 | NULL | 0 | 4 | osdemo01 | nova-compute | compute | 37050 | 0 | nova | | 2011-01-30 23:42:24 | 2011-02-03 06:55:44 | NULL | 0 | 9 | osdemo04 | nova-compute | compute | 28484 | 0 | nova | | 2011-01-30 21:27:28 | 2011-02-03 06:54:23 | NULL | 0 | 8 | osdemo05 | nova-compute | compute | 29284 | 0 | nova | +---------------------+---------------------+------------+---------+----+----------+----------------+-----------+--------------+----------+-------------------+ You can see that 'osdemo0{1,2,4,5} are all running 'nova-compute.' When you start spinning up instances, they will allocate on any node that is running nova-compute from this list.