Amazon has announced a new feature of booting instances from EBS volume. This feature changes radically the way how AWS instances can be preserved if compared to the traditional volume bundling and uploading to S3.

Though this all sounds nice, it isn’t really too easy to convert existing instaces to boot from EBS. All previous instances boot from the local instance disk. Amazon AWS management console indicates the location where the instance boots with the Root Device Type column. Previous instances have the root device type as instance-store while EBS images have the type as ebs.

To get started with the EBS images, there are a few images from Amazon which are useful as a base image. It was really easy to just boot one of them and mount one EBS volume which contained a snapshot of the database and the www root. Installing basic LAMP stuff, changes in httpd.conf and my.cnf to point in the EBS volume and the AWS instance which boots from EBS was ready. I could now create snapshots of the system in minutes and also shut down the system when I don’t need it and thus not get billed for the instance. Awesome! The snapshot also had the EBS volume snapshotted which was mounted to the instance.

The EBS image feature is likely to open a wide range of new applications and really change the way how an elastic service is been constructed. Basically, a member of a pool of web servers can now be created in advance and just turned on when there is a demand to use it. Of course, it first must update itself to be on par with the other pool members.

I am not really sure if it was my old lap top which I used to work with the EBS images or what, but the AWS management console was painfully slow in responding, especially when using Firefox. And when using IE, I did not get anything else in the pop-up window than the button to create the snapshot:

createImage

Firefox, though really slow in responding, gave the option of typing the name in the required field. Also, if you create EBS image and then decide to get rid of the EBS image, you have to delete the AMI first, otherwise the management console will complain that it’s in use.

I have yet to decide should I go with the instance-store or EBS with my instance. It will add something to my costs of running my site in AWS, but that shouldn’t be too much. I find a lot more benefits with EBS than running in instance-store, but then again I fear getting lazy in responding to possible threats of instances going down and disaster recovery.

Pauli Haikonen