Instances are virtual machines that run inside the cloud. To start an instance, a virtual machine image must exist that contains the following information: which operating system to use, a username and password with which to log in to the instance, file storage, etc. The cloud contains a pool of such images that have been uploaded to OpenStack Image and are accessible to members of different projects.
When starting an instance, specify the following key parameters:
In OpenStack, flavors define the compute, memory, and storage capacity of
nova
computing instances. To put it simply, a flavor
is an available hardware configuration for a server. It defines the
“size” of a virtual server that can be launched.
For more details and a list of default flavors available, refer to the Administrator Guide, chapter Dashboard or chapter OpenStack command-line clients, section Manage Flavors. The guide is available from http://www.suse.com/documentation.
Key Pairs are SSH credentials that are injected into images when they
are launched. For this to work, the image must contain the
cloud-init
package.
It is recommended to create at least one key pair per project. If you already have generated a key pair with an external tool, you can import it into OpenStack. The key pair can be used for multiple instances belonging to that project.
For details, refer to the End User Guide, chapter OpenStack dashboard or chapter OpenStack command-line clients, section Configure access and security for instances. The guide is available from http://www.suse.com/documentation.
In SUSE OpenStack Cloud, security groups are used to define which incoming network traffic should be forwarded to instances. Security groups hold a set of firewall policies (security group rules).
For details, refer to the End User Guide, chapter OpenStack dashboard or chapter OpenStack command-line clients, section Configure access and security for instances. The guide is available from http://www.suse.com/documentation.
Instances can belong to one or multiple networks. By default, each instance is given a fixed IP address, belonging to the internal network.
You can launch instances from the following sources. For details, see the End User Guide, chapter OpenStack dashboard or chapter OpenStack command-line clients, section Launch and manage instances. The guide is available from http://www.suse.com/documentation.
Images that have been uploaded to SUSE OpenStack Cloud.
Volumes that contain images.
Instance snapshots.
Volume snapshots.
For instructions on how to launch instances from images or snapshots, see Launch an Instance.