I need help duplicating Amazon AWS EC2 instances

Question

I\'m just getting started with AWS EC2 and not entirely sure I understand it.

From what I\'ve read, an instance is basically a virtual server, and you should be able to

Answer 1

Create a webserver AMI using EBS backed instance. This will serve as your template for running multiple web-server instance later.

For the app codes, depending on your strategy and amount of files to transfer, you can pull them from S3 or git or maybe using a centralized filesystem such as NFS.

Configure the ELB, add one or more web server instances to it. CNAME your ELB's public dns to your www.domain.com.

Answer 2

You don't really "duplicate" the instance. You more copy it as a "blueprint". Then when you boot an instance later, you can base that instance off of your snapshot or "blueprint".

The ELB can be configured to point at any instance you want, so when you boot a new server off this snapshot/"blueprint" it can be automatically added to the ELB.

Now that is cleared up, to answer the question:

1. I would make sure to use EBS backed instances. You can find them all over. But not S3 backed. If they EBS backed then the exact volume with all your configs will be there.

2. I would make sure your instance is configured how you like it and has proper scripts installed for when it boots up. You will want your services started, config files pulled down from repositories, etc. The config files should be there, but I would not rely on that. If you have them in a repository and then make a startup script to pull them down and copy them where you want, you will be in much better shape.

3. With the instance running and selected, click on the instance actions drop down and click "Create AMI"

4. The instance will REBOOT. So be careful.

5. Launch a new instance. And pick the AMI/Snapshot that #3 created.

6. Done. Check this https://stackoverflow.com/a/8919031/667608 that could help with the above.

Oh, one other thing, if you have any EBS Volumes attached, they will also be copied, but you will need to mount them once the server boots.

Answer 3

Under instances, click on the image you want to duplicate and then go to instance action(its near the top) and create ami.

This creates a snapshot of your image as it is right now. Then when you need to add more power, you can simply launch that ami and have the load balancer distrubute the traffic between those ami's.

On a side note, unless really required, I would not suggest you store data on the ami if its changing and you plan to use it on another launched ami. You'll pretty much have to keep taking ami snapshots to update it with the new data, so instead figure a way to maintain state somewhere else(not sure about your data but you can consider a database, s3, or another server that these servers can mount to get the same data).

Hope that helps!