EC2 Instance scheduled for retirement

Amazon generally destroys the hardware periodically, if your instance is on that rack then you will get notified that instance will get retire after certain period.

If you stop and start the instance, Amazon by default will move your instance to different rack.

I am not exactly sure of the time period but last time I have checked they destroy their hardware after 2 years.

Usually you will get notified months before instance is terminated.

Thus stop and start the instance will work note not restart.

Edit: Here is the reference link

Hope that helps

I suggest you take an image of your instance and launch a new instance from it. Then terminate your old instance. We have had the same issue several times.