One of the features I like most about virtualization is that new virtual disks can be added so easily. If you are working in the cloud this is even more fun. The difference between cloud computing and common virtualization is that you don’t have to worry about the available physical disk capacity with the former. You need another 100 Terabyte? Just create a new Elastic Block Storage (EBS) volume with a mouse click. Of course, you have to pay for the provisioned storage. 1TB costs $100 per month. This is not really cheap. Flexibility and scalability have their price. Volumes can be easily attached to an Instance. This works similar to other virtualization solutions. Volumes can be attached only to running Instances, though. Once the volume is attached, you have to add the drive with the Windows Disk Management applet and format the volume. You can detach a volume while the Instance is running. If you re-attach a formatted volume, you only have to reactivate it with Windows Disk Management.

You can also create “snapshots” of volumes with the AWS Management Console. In Amazon’s terminology, a snapshot is basically a copy of a volume. To attach it to an Instance, you have to create a new volume that is based on the snapshot. You can also delete the original volume without affecting the snapshot. It is strange, however, that Amazon charges a monthly fee of $0.15 per GB for snapshots whereas volumes that were created rather than copied cost only $0.10 (prices for the US region).

During my test, a volume “hanged” once; that is, I couldn’t delete it through the AWS Management Console. I made the mistake of attaching it to an Instance while a bundling task (topic of my next post) was running for this virtual machine. I had to use Amazon API command tools to force the deletion of the volume. This demonstrates that the AWS Management Console has its limitations.

Source: http://4sysops.com/archives/amazon-ec2-aws-management-console-volumes-and-snapshots/