EC2 and Persistent Storage

April 14th, 2008

Coming this year, Amazon EC2 will have persistent storage. Today the ‘disk’ per instance is ephemeral. If the instance gets a reboot or is shuted down, you lost all the information you had on that disk. So, you couldn’t use things like relational databases on EC2 without using some sort of S3 hack and play with MySQL replication plus the geographical feature of EC2. Basically you make incremental backups of the database to S3 every 10m, run a full backup once per day and launch another MySQL instance on a separate datacenter for mirroring. Now, you’ll have the possibility to buy a volume from 1G to 1T, mount it on your EC2 instance and there you go. Oh, btw, you have snapshots, too. Quoting Jeff Barr: 

In the same way that your running EC2 instances, your Elastic IP addresses, your S3 buckets and your SQS queues can be thought of as items contained within the scope of your AWS account, our forthcoming persistent storage feature will give you the ability to create reliable, persistent storage volumes for use with EC2. Once created, these volumes will be part of your account and will have a lifetime independent of any particular EC2 instance.These volumes can be thought of as raw, unformatted disk drives which can be formatted and then used as desired (or even used as raw storage if you’d like). Volumes can range in size from 1 GB on up to 1 TB; you can create and attach several of them to each EC2 instance. They are designed for low latency, high throughput access from Amazon EC2. Needless to say, you can use these volumes to host a relational database.You will also be able to perform “snapshot” backups of your volumes to Amazon S3. You can use these snapshots to create new volumes or to roll back your stored data to an earlier point in time.    

For now, a few lucky bastards are on the beta tests. They expect to open it to a wider audience later this year. World domination for Amazon? How can you compete in vm hosting business or cloud computing? Let’s have a look a the pricing numbers. Can’t wait.

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