Question

I booted up an EC2 instance months ago and at that time I had the .pem key stored in my PC. The PC since crashed and I had to reinstall Windows on it and I don’t have a backup of the .pem file

Is there any way at all for me to get to the prompt on the EC2 instance- any way to ssh or otherwise get to the instance?

Answer 1

Not easily.

Guidance on the forums indicate that you can kind of do it by generating a new key pair and then bringing up a new instance and mounting the volume from the original instance and installing the keypair in that volume. After that the original instance should be able to use the new keypair.

According to this post on AWS Developer Forums it can be accomplished via:

Creating a new keypair downloads the private key to your machine and the public key is stored in your AWS account. When you launch a new (linux) instance the public key is placed into the /root/.ssh/authorized_keys file (or /home/ubuntu/.ssh/authorized_keys for Canonical Ubuntu AMIs), allowing your private key access to the instance.

Losing the private key can be fixed by logging in to the instance via another linux account if you have set one up.

Alternatively, if you’re running an EBS-backed instance then you can Stop it, attach the root EBS volume to another instance, and place a new public key into the authorized_keys file, then return the volume to the original (stopped) instance and Start the instance again.

If none of these work, then – sorry – you’re out of luck. It’s called a key because you can’t get in without it.