An annoying feature of Amazon EC2, a service which provides virtual servers on demand, is that server instances have no persistent storage. Any data written to the virtual hard drive disappears when the instance shuts down. Developers have needed to store data elsewhere, such as in Amazon’s S3 storage service.
Amazon has now announced persistent storage. These are virtual hard drives that you can attach to EC2 instances. Another enhancement since the initial launch is static IP numbers. Early tester (and reseller) Thorsten von Eicken is enthusiastic:
The feature that really makes the storage volumes sizzle is the ability to snapshot them to S3 and then create new volumes from the snapshots. The snapshots are great for durability: once a snapshot is taken it is stored in S3 with all the reliability attributes of S3, namely redundant storage in multiple availability zones. This essentially solves the whole backup issue with one simple API call.
It’s an excellent feature which arguably should have been there from the start.
Incidentally, I don’t know why people keep comparing Amazon’s web services with Google’s App Engine. OK, they are both cloud services. But Amazon is providing infrastructure services; Google is offering an application runtime. They hardly compete at all. Google and Amazon compete in other ways: Amazon marketplace vs Google Base and Google Checkout, for example.