When you launch an instance from an image, OpenStack creates a local copy of the image on the compute node where the instance starts.
When you launch an instance from a volume, note the following steps:
To select the volume to from which to launch, launch an instance from an arbitrary image on the volume. The image that you select does not boot. Instead, it is replaced by the image on the volume that you choose in the next steps.
To boot a Xen image from a volume, the image you launch in must be the same type, fully virtualized or paravirtualized, as the one on the volume.
Select the volume or volume snapshot from which to boot. Enter a device name. Enter
vdafor KVM images orxvdafor Xen images.
Log in to the dashboard, choose a project, and click Images & Snapshot.
The dashboard shows the images that have been uploaded to OpenStack Image Service and are available for this project.
For details on creating images, see Creating images manually in the OpenStack Virtual Machine Image Guide.
Select an image and click .
In the Launch Instance dialog box, specify the following values:
Details tab Availability Zone
By default, this value is set to the availability zone given by the cloud provider (for example,
us-westorapac-south). For most cases, it could benova.Instance Name
Assign a name to the virtual machine.
![[Note]](../common/images/admon/note.png)
Note The name you assign here becomes the initial host name of the server. After the server is built, if you change the server name in the API or change the host name directly, the names are not updated in the dashboard.
Server names are not guaranteed to be unique when created so you could have two instances with the same host name.
Flavor
Specify the size of the instance to launch.
Instance Count
To launch multiple instances, enter a value greater than 1. The default is 1.
Instance Boot Source
Your options are:
Boot from image—If you choose this option, a new field for Image Name displays. You can select the image from the list.
Boot from snapshot—If you choose this option, a new field for Instance Snapshot displays. You can select the snapshot from the list.
Boot from volume—If you choose this option, a new field for Volume displays. You can select the volume from the list.
Boot from image (creates a new volume) —With this option, you can boot from an image and create a volume by entering the Device Size and Device Name for your volume.
Boot from volume snapshot (creates a new volume)— Using this option, you can boot from a volume snapshot and create a new volume by choosing Volume Snapshot from a list and adding a Device Name for your volume.
Since you are launching an instance from an image, Boot from image is chosen by default.
Image Name
This field changes based on your previous selection. Since you have chosen to launch an instance using an image, the Image Name field displays. Select the image name from the dropdown list.
Access & Security tab Keypair
Specify a key pair.
If the image uses a static root password or a static key set (neither is recommended), you do not need to provide a key pair to launch the instance.
Security Groups
Activate the security groups that you want to assign to the instance.
Security groups are a kind of cloud firewall that define which incoming network traffic is forwarded to instances. For details, see the section called “Add a rule to the default security group”.
If you have not created any security groups, you can assign only the default security group to the instance.
Networking tab Selected Networks
To add a network to the instance, click the in the Available Networks field.
Post-Creation tab Customization Script
Specify a customization script that runs after your instance launches.
Click .
The instance starts on a compute node in the cloud.
The Instances tab shows the instance's name, its private and public IP addresses, size, status, task, and power state.
If you did not provide a key pair, security groups, or rules, users can access the instance only from inside the cloud through VNC. Even pinging the instance is not possible without an ICMP rule configured. To access the instance through a VNC console, see the section called “Access an instance through a console”.
