Last week, Amazon Web Services released a great killer new feature in their virtual computing cloud EC2. You can now launch AWS instances (virtual servers) from an EBS (Elastic Block Storage). An Elastic Block Storage is like a USB hard drive you can plug in and out of your virtual server to expand space or back-up data. Now, you can boot your instances from an EBS which is great for testing your web apps and lowering costs. Here’s why this new feature rocks:
Previously when you would terminate/shut down your instance, all data would be lost and you would need to boot up a new instance from a default or self-configured AMI (instance images). The default AMI’s are quite great, Amazon and all kind of community people have set up a lot of AMI’s you can use with Windows, Fedora, Ubuntu, you name it. However, when launching an instance from a template, you will have to install your own software (like nginx, Apache or Ruby on Rails) over and over again. You can create your own AMI’s, but the process is technical and quite hard so I actually never had the chance to build my own one. With the new boot-from-EBS feature, in the AWS Console you can now create an AMI on the fly from a currently running instance and save it on an EBS to boot from. This saves you a lot of time on setting up your AMI and updating the software on it. The only downside is that you will pay for all the EBS storage, which is probably bigger than storing an AMI on S3.
But, this gives us a great opening for easily testing our web applications. You can now just create a bootable EBS with your self-configured AMI on it and run the instance when you would like to test your app or show it to a customer in a real-life server environment, and not locally on your laptop or development server you still have in a dusty corner of your office. Because you can now Stop the instance in stead of Terminating it. All data will be preserved without having to attach other EBSes with all your files and databases and such.
In the end you will have your testing instance up faster and maintaining the required software on it is a much simpler task, you just create new bootable EBS disks from your instance and launch them. Also, because you can now Stop the instance in stead of terminating, you only pay for storing the EBS image and not running your test server all the time.
You could provide a great service for your customers that they can push a button on your admin panel and the server with the app could go live when they requested it, without you even knowing they are testing or having to set up the instance of your web app manually. I see great time and cost-saving service opportunities here 
