Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Status checks for your instances

With instance status monitoring, you can quickly determine whether Amazon EC2 has detected any problems that might prevent your instances from running applications. Amazon EC2 performs automated checks on every running EC2 instance to identify hardware and software issues. You can view the results of these status checks to identify specific and detectable problems. The event status data augments the information that Amazon EC2 already provides about the state of each instance (such as pending, running, stopping) and the utilization metrics that Amazon CloudWatch monitors (CPU utilization, network traffic, and disk activity).

Status checks are performed every minute, returning a pass or a fail status. If all checks pass, the overall status of the instance is OK. If one or more checks fail, the overall status is impaired. Status checks are built into Amazon EC2, so they cannot be disabled or deleted.

When a status check fails, the corresponding CloudWatch metric for status checks is incremented. For more information, see Status check metrics. You can use these metrics to create CloudWatch alarms that are triggered based on the result of the status checks. For example, you can create an alarm to warn you if status checks fail on a specific instance. For more information, see Create and edit status check alarms.

You can also create an Amazon CloudWatch alarm that monitors an Amazon EC2 instance and automatically recovers the instance if it becomes impaired due to an underlying issue. For more information, see Recover your instance.

Types of status checks

We provide system status checks and instance status checks.

System status checks

System status checks monitor the Amazon systems on which your instance runs. These checks detect underlying problems with your instance that require Amazon involvement to repair. When a system status check fails, you can choose to wait for Amazon to fix the issue, or you can resolve it yourself. For instances backed by Amazon EBS, you can stop and start the instance yourself, which in most cases results in the instance being migrated to a new host. For Linux instances backed by instance store, you can terminate and replace the instance. For Windows instances, the root volume must be an Amazon EBS volume; instance store is not supported for the root volume. Note that instance store volumes are ephemeral and all data is lost when the instance is stopped.

The following are examples of problems that can cause system status checks to fail:

If a system status check fails, we increment the StatusCheckFailed_System metric.

Bare metal instances

If you perform a restart from the operating system on a bare metal instance, the system status check might temporarily return a fail status. When the instance becomes available, the system status check should return a pass status.

Instance status checks

Instance status checks monitor the software and network configuration of your individual instance. Amazon EC2 checks the health of the instance by sending an address resolution protocol (ARP) request to the network interface (NIC). These checks detect problems that require your involvement to repair. When an instance status check fails, you typically must address the problem yourself (for example, by rebooting the instance or by making instance configuration changes).

The following are examples of problems that can cause instance status checks to fail:

If an instance status check fails, we increment the StatusCheckFailed_Instance metric.

Bare metal instances

If you perform a restart from the operating system on a bare metal instance, the instance status check might temporarily return a fail status. When the instance becomes available, the instance status check should return a pass status.

View status checks

You can view and work with status checks using the Amazon EC2 console or the Amazon CLI.

View status using the console

To view status checks using the Amazon EC2 console, perform the following steps.

View status using the command line

You can view status checks for running instances by using the describe-instance-status (Amazon CLI) command.

To view the status of all instances, use the following command.

aws ec2 describe-instance-status

To get the status of all instances with an instance status of impaired, use the following command.

aws ec2 describe-instance-status \
    --filters Name=instance-status.status,Values=impaired

To get the status of a single instance, use the following command.

aws ec2 describe-instance-status \
    --instance-ids i-1234567890abcdef0

Alternatively, use the following commands:

Report instance status

You can provide feedback if you are having problems with an instance whose status is not shown as impaired, or if you want to send Amazon additional details about the problems you are experiencing with an impaired instance.

We use reported feedback to identify issues impacting multiple customers, but do not respond to individual account issues. Providing feedback does not change the status check results that you currently see for the instance.

Report status feedback using the console

Report status feedback using the command line

Use the report-instance-status (Amazon CLI) command to send feedback about the status of an impaired instance.

aws ec2 report-instance-status \
    --instances i-1234567890abcdef0 \
    --status impaired \
    --reason-codes code

Alternatively, use the following commands:

Create and edit status check alarms

You can use the status check metrics to create CloudWatch alarms to notify you when an instance has a failed status check.

Create a status check alarm using the console

Use the following procedure to configure an alarm that sends you a notification by email, or stops, terminates, or recovers an instance when it fails a status check.

If you need to make changes to an instance status alarm, you can edit it.

Create a status check alarm using the Amazon CLI

In the following example, the alarm publishes a notification to an SNS topic, arn:aws-cn:sns:us-west-2:111122223333:my-sns-topic, when the instance fails either the instance check or system status check for at least two consecutive periods. The CloudWatch metric used is StatusCheckFailed.