Create Multiple Instances from Image

You can create multiple instances from an existing image. Multiple instances can be created when you require multiple servers in scenarios where there is a considerable amount of data processing load to be managed by the applications deployed on the instances.

When you create an instance, you must specify what image to create the instances from.

Before you create an instance, ensure that the required images, networks, volumes, and flavors are available to you. If you wish to allow access to the instance through SSH, ensure that the administrator has created the required SSH key pair.

An instance can connect to one or more virtual or physical networks.

While creating an instance, it is necessary to specify the set of firewall rules to control the incoming and outgoing network traffic for the instance. The set of firewall rules is called the security group.

You can select at least one or more networks that the instance should connect to. These networks could be physical or virtual networks.

You can customize your instance with cloud-init. Cloud-init is a Python-based multi-distribution package that handles early initialization of the cloud instance. You can use cloud-init script, up to 64 KB, in size to initialize the cloud instance after it launches.

You must be a self-service user or an administrator to perform this operation.

To create an instance, follow the steps given below.

  1. Log in to Clarity.
  2. Click Instances in the left panel.
  3. Click New VM Instance seen on the top right corner.
  4. Select Image option as VM Source Type.
  5. Select the required image in the list of images.
  6. Click Next.
  7. Optionally, select the availability zone for the instance.
  8. Select the flavor to use for the instance from the list of available flavors.
  9. Click Next.
  10. Select the checkboxes for one or more networks for the instance.
  11. Click Next.
  12. Enter an instance name.
  13. Select the SSH key pair to use. If you do not wish to use SSH key pairs, you can leave the default value as None.
  14. Add a server group. If you do not wish to use SSH key pairs, you can leave the default value as None.
  15. Select one or more security groups for firewall rules.
  16. Select the Create Multiple Instances check box. Multiple Instances
  17. Enter the desired number of instances to create.
  18. Enter the names for each of the instances in the text boxes that appear after entering number of instances to create.
  19. Click Next.
  20. Click the Yes check box if you want to use configuration drive. This is an optional step.
  21. In order to customize the instance after it launches, paste the script or the cloud-init file content in the blank space provided. This is an optional step.
  22. Click Next to review the instance configuration.
  23. Click Create Instance to create the instances.
  24. Record the username and passwords that are generated and displayed on the page.

You can click Back to go back and make corrections or changes to the configuration before creating the instances. When you create the instances, the instances starts automatically.

Fixed IP addresses are assigned to the instances, by default. The fixed IP address is the private IP address of an instance.

If you wish to make the instance publicly available, you can manually assign a floating IP address to it. The instance is reachable over the Internet by the floating IP address. You can assign the floating IP address to an instance from a pool of floating IP addresses available to you.

Once the instances are created, you can attach volumes to the individual instances, if required.