Sudden reboot of t2.small EC2 Instance Sept 5 2024 12:51 UTC

Question

Hi there,

is there any possible explanations for why my t2.small EC2 instance (located in eu-central-1a) was suddenly rebooted today around 12:51 UTC? Any known incidents?

After the reboot, the server keys were regenerated, and the authorized keys file was modified. I was still able to log in by disabling host key verification.

Thank you.

Praveen Kumar K · Answer

Hello,

Reason might be:
1. The underlying hardware that's hosting your instance is faulty, and Amazon EC2 restarts the instance to move it to a new, healthy hardware. (unplanned). If any issues AWS will sent Notice soon[ via PHD notice](https://docs.aws.amazon.com/health/latest/ug/getting-started-health-dashboard.html).
2. Scheduled maintenance occurs on your instance that initiates a reboot. (planned) ([Check PHD notice](https://docs.aws.amazon.com/health/latest/ug/getting-started-health-dashboard.html))
3. A user or application [inside your server reboots the instance](https://serverfault.com/questions/675931/how-to-find-out-who-rebooted-linux-server).
4. A user or other serive which using IAM role reboot the instance using AWS API. To check use [cloud trail.](https://repost.aws/knowledge-center/ec2-windows-identify-stop-reboot)

Ref: 
[+] https://repost.aws/knowledge-center/ec2-instance-automatic-reboot-cause

Sudden reboot of t2.small EC2 Instance Sept 5 2024 12:51 UTC

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