Amazon EC2 instance state changes

An Amazon EC2 instance transitions through different states from the moment you launch it through to its termination.

The following illustration represents the transitions between instance states.

You can receive notifications when your instances change states. For more information, see State change events for Amazon EC2 instances.

Billing by instance state

The following table provides a brief description of each instance state and indicates whether instance usage is billed. Some AWS resources, such as Amazon EBS volumes and Elastic IP addresses, incur charges regardless of the instance's state. For more information, see Avoiding Unexpected Charges in the AWS Billing User Guide.

Pending instances

When you launch an instance, it enters the pending state. The instance type that you specified at launch determines the hardware of the host computer for your instance. We use the Amazon Machine Image (AMI) you specified at launch to boot the instance. After the instance is ready for you, it enters the running state. You can connect to your running instance and use it the way that you'd use a computer sitting in front of you.

As soon as your instance transitions to the running state, you're billed for each second, with a one-minute minimum, that you keep the instance running, even if the instance remains idle and you don't connect to it.

Stopped instances

If your instance fails a status check or is not running your applications as expected, and if the root volume of your instance is an Amazon EBS volume, you can stop and start your instance to try to fix the problem.

When you stop your instance, it enters the stopping state, and then the stopped state. You are not charged for usage or data transfer fees for your instance when it is stopped. Charges are incurred for the storage of any Amazon EBS volumes. While your instance is in the stopped state, you can modify certain attributes of the instance, including the instance type.

When you start your instance, it enters the pending state, and the instance is moved to a new host computer (though in some cases, it remains on the current host). When you stop and start your instance, you lose any data on the instance store volumes attached to the previous host computer.

Your instance retains its private IPv4 address, which means that an Elastic IP address associated with the private IPv4 address or network interface remains associated with your instance. If your instance has an IPv6 address, it retains the IPv6 address.

Each time you transition an instance from stopped to running, you are charged per second when the instance is running, with a minimum of one minute per instance start.

For more details about stopping and starting an instance, see Stop and start Amazon EC2 instances.

Hibernated instances

When you hibernate an instance, we signal the operating system to perform hibernation (suspend-to-disk), which saves the contents from the instance memory (RAM) to your Amazon EBS root volume. We persist the instance's Amazon EBS root volume and any attached Amazon EBS data volumes. When you start your instance, the Amazon EBS root volume is restored to its previous state and the RAM contents are reloaded. Previously attached data volumes are reattached and the instance retains its instance ID.

When you hibernate your instance, it enters the stopping state, and then the stopped state. We don't charge usage for a hibernated instance when it is in the stopped state, but we do charge while it is in the stopping state, unlike when you stop an instance without hibernating it. We don't charge usage for data transfer fees, but we do charge for the storage for any Amazon EBS volumes, including storage for the RAM data.

When you start your hibernated instance, it enters the pending state, and we move the instance to a new host computer (though in some cases, it remains on the current host).

Your instance retains its private IPv4 address, which means that an Elastic IP address associated with the private IPv4 address or network interface is still associated with your instance. If your instance has an IPv6 address, it retains its IPv6 address.

For more information, see Hibernate your Amazon EC2 instance.

Rebooting instances

You can reboot your instance using the Amazon EC2 console, a command line tool, and the Amazon EC2 API. We recommend that you use Amazon EC2 to reboot your instance instead of running the operating system reboot command from your instance.

Rebooting an instance is equivalent to rebooting an operating system. The instance remains on the same host computer and maintains its public DNS name, private IP address, and any data on its instance store volumes. It typically takes a few minutes for the reboot to complete, but the time it takes to reboot depends on the instance configuration.

Rebooting an instance doesn't start a new instance billing period; per second billing continues without a further one-minute minimum charge.

For more information, see Reboot your instance.

Terminated instances

When you've decided that you no longer need an instance, you can terminate it. As soon as the status of an instance changes to shutting-down or terminated, you stop incurring charges for that instance.

If you enable termination protection, you can't terminate the instance using the console, CLI, or API.

After you terminate an instance, it remains visible in the console for a short while, and then the entry is automatically deleted. You can also describe a terminated instance using the CLI and API. Resources (such as tags) are gradually disassociated from the terminated instance, therefore may no longer be visible on the terminated instance after a short while. You can't connect to or recover a terminated instance.

Each Amazon EBS-backed instance supports the InstanceInitiatedShutdownBehavior attribute, which controls whether the instance stops or terminates when you initiate shutdown from within the instance itself (for example, by using the shutdown command on Linux). The default behavior is to stop the instance. You can modify the setting of this attribute while the instance is running or stopped.

Each Amazon EBS volume supports the DeleteOnTermination attribute, which controls whether the volume is deleted or preserved when you terminate the instance it is attached to. The default is to delete the root device volume and preserve any other EBS volumes.

For more information, see Terminate Amazon EC2 instances.

Differences between instance states

The following table summarizes the key differences between rebooting, stopping, hibernating, and terminating your instance.

Operating system shutdown commands always terminate an instance store-backed instance. You can control whether operating system shutdown commands stop or terminate an Amazon EBS-backed instance. For more information, see Change the instance initiated shutdown behavior.