Cannot connect to running instance using EC2 console connect feature

Question

I have a instance  configured in EC2. I was able to connect to the instance using both SSH and the Connect feature in the EC2 console. After I installed Postgres 14 on the server, I lost contact.

I rebooted the instance from the console, but still no connection from either SSH or EC2 Connect. I have valuable data on the server. How can I reestablish communication with the instance?

Accepted Answer

Hello.

Looking at the situation, there is a possibility that the EC2 specifications are insufficient due to the Install of PostgreSQL.  
How about temporarily increasing the instance size?  
Please follow the steps in the document below to check the system logs and check for any errors.  
https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/troubleshoot-unreachable-instance.html#instance-console-console-output

Also, in the worst case scenario, consider attaching the EBS root volume to a healthy EC2 to salvage important data.  
https://repost.aws/knowledge-center/ec2-linux-emergency-mode

Also, it may be possible to connect via a serial console, so please try that.  
https://repost.aws/knowledge-center/ec2-linux-ssh-troubleshooting

Answer

Check the EC2 metrics (CPU and memory).
If either utilization is high, you may be running out of resources due to the installation and startup of PostgreSQL.

In this case, a simple solution is to change the instance type to one with better specifications.

Otherwise, if the OS is failing to start, you can check the status by checking the instance console output or the instance screenshot.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/troubleshoot-unreachable-instance.html

Cannot connect to running instance using EC2 console connect feature

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