Instances are virtual machines that run inside the cloud. You can launch an instance directly from one of the available OpenStack images. The OpenStack Image Service provides a pool of images that are accessible to members of different projects. When you launch an instance from an image, OpenStack creates a local copy of the image on the respective compute node where the instance is started. Alternatively, you can launch an instance from an image that you have copied to a persistent volume. To launch an instance, specify the following parameters: The instance source, which is an image or snapshot. Alternatively, you can boot from a volume, which is block storage, to which you've copied an image or snapshot. The image or snapshot, which represents the operating system. A name for your instance. The flavor for your instance, which defines the compute, memory, and storage capacity of nova computing instances. A flavor is an available hardware configuration for a server. It defines the size of a virtual server that can be launched. Access and security credentials, which include one or both of the following credentials: A keypair for your instance, which are SSH credentials that are injected into images when they are launched. For this to work, the image must contain the cloud-init package. Create at least one keypair for each project. If you already have generated a keypair with an external tool, you can import it into OpenStack. You can use the keypair for multiple instances that belong to that project. A security group, which defines which incoming network traffic is forwarded to instances. Security groups hold a set of firewall policies, known as security group rules. If needed, you can assign a floating (public) IP address to a running instance and attach a block storage device, or volume, for persistent storage. Log in to the OpenStack dashboard. If you are a member of multiple projects, select a project from the drop-down list at the top of the Project tab. Click the Images & Snapshot category. The dashboard shows the images that have been uploaded to OpenStack Image Service and are available for this project. Select an image and click Launch. The Launch Image window appears:

Specify the following parameters: Enter an instance name to assign to the virtual machine. From the Flavor drop-down list, select the size of the virtual machine to launch. Optionally, select a keypair. In case an image uses a static root password or a static key set (neither is recommended), you do not need to provide a keypair on starting the instance. In Instance Count, enter the number of virtual machines to launch from this image. Assign the instance to the default security group. If you added rules to this group, the instance implements these rules. Click Launch Instance. The instance is launched on any of the compute nodes in the cloud. After you have launched an instance, switch to the Instances & Volumes category to view the instance name, its (private or public) IP address, size, status, task, and power state.

If you did not provide a keypair on starting and have not touched security groups or rules so far, by default the instance can only be accessed from inside the cloud through VNC at this point. Even pinging the instance is not possible.