AWS EC2 Instance Not Reachable anymore

Question

My previously working ec2 instance is suddenly not accessible through SSH or HTTP. This is what I have tried so far:

1. Rebooting Instance
2. Shutting down and starting up
3. My instance system logs are empty
4. Created new instance, detached volume and attached volume to new instance. I did not delete previous volume (Kinda scared of deleting anything, am new to aws)

My instance configuration is Amazon linux x86. Its failing Instance Status Checks. Any direction, help will be very appreciated.

Answer 1

The easiest way to deal with rogue instances is to

1. Stop them
2. Create a new instance in the same region and same zone (i.e., us-east-1b), t2.micro is fine for this
3. Detach the volume from the rogue instance (helps to name it)
4. Attach that volume to the new instance (just like plugging in a new disk drive)
5. Log into your new instance
6. Mount the volume and investigate what happened— chances are good a startup file's misconfigured.
7. After fixing the volume, unmount it, and then you can force-detach it.
8. Reattach your volume to the previous instance (this time specify the device to serve as the root volume, usually /dev/sda1).
9. Boot the rogue instance— if you can.

Rinse, and repeat until you've solved the problem. Destroy the other instance when you're done or suffer the bill to leave it running.

Answer 2

Create a spot instance, see if you can connect using ssh or http from the spot instance. If you can then it's a network issue causing your problems. If not then you can try Ryder's instructions above.

Also try connecting to the new spot instance from your workstation.

It could also be your security group or ACL preventing access. Try opening them up to 0.0.0.0/0 temporarily.