Problem
When the option to deregister managed nodes in AWS Systems Manager (SSM) appears greyed out, it indicates that the nodes are not in a deregisterable state. However, there are alternative steps you can take to deregister them. Here’s a detailed guide on how to deregister managed nodes in AWS SSM when the deregistering option is greyed out: Here’s a detailed guide on how to deregister managed nodes in AWS SSM when the deregistering option is greyed out also see the link to the AWS site
Please see the screenshot below to where the option to deregister is “greyed out”
Deregistering managed nodes in a hybrid and multicloud environment
- Verify node status: Before proceeding with the deregistration, ensure that the nodes you want to deregister are currently running and connected to the AWS SSM service. You can confirm this by checking the instance status in the EC2 console.
- Check managed instance associations: If the deregistering option is greyed out, it may be because the managed nodes have active associations with other AWS services, such as AWS Systems Manager Automation or State Manager. These associations can prevent immediate deregistration. To proceed, you will need to remove or disable these associations.
- Remove associations: To remove the associations, navigate to the AWS Systems Manager console. From there, access the Automation or State Manager sections, depending on the associations present. Locate the associations related to the nodes you want to deregister and delete or disable them accordingly.
- Verify association removal: After removing or disabling the associations, confirm their removal by checking the association status in the respective sections of the AWS Systems Manager console. Ensure that the associations are no longer active.
- Retry deregistering: Once the associations are removed, return to the EC2 console and select the nodes you want to deregister. Click on the “Actions” dropdown menu, and this time the option to deregister should no longer be greyed out. Choose the deregister option to initiate the process.
- Confirm deregistration: After initiating the deregistration process, a confirmation prompt may appear. Review the details and confirm the action to proceed with the deregistration.
Resolution
In a hybrid environment, you have the ability to deregister an instance even if it is online and not hosted on AWS. However, if the instance is an EC2 instance and it has been registered with SSM Fleet Manager, you won’t be able to deregister it while it is still running. The deregistration process can only take place when the EC2 instance is terminated.
