Launches the specified number of instances using an AMI for which you have permissions.

When you launch an instance, it enters the pending state. After the instance is ready for you, it enters the running state. To check the state of your instance, call DescribeInstances.

If you don't specify a security group when launching an instance, Amazon EC2 uses the default security group. For more information, see Security Groups in the Amazon Elastic Compute Cloud User Guide .

Linux instances have access to the public key of the key pair at boot. You can use this key to provide secure access to the instance. Amazon EC2 public images use this feature to provide secure access without passwords. For more information, see Key Pairs in the Amazon Elastic Compute Cloud User Guide .

You can provide optional user data when launching an instance. For more information, see Instance Metadata in the Amazon Elastic Compute Cloud User Guide .

If any of the AMIs have a product code attached for which the user has not subscribed, RunInstances fails.

For more information about troubleshooting, see What To Do If An Instance Immediately Terminates , and Troubleshooting Connecting to Your Instance in the Amazon Elastic Compute Cloud User Guide .