Ubuntu images on AWS, especially the minimal, has a too big EBS volume size

[Rasmus Mikkelsen]

For images on AWS the EBS volume size should be reduced to better match the size of the content and not merely been 8GB as it is for minimal and server.

After having done several tests on AMIs, it seems that EBS volume size of the AMI being used to provision an EC2 instance, has a significant impact on the time it takes for an instance to become ready. It doesn't matter if the EBS volume actually contains files or not, just the size.

In addition, its not possible to create an EC2 instance with an EBS volume that has a smaller size than the one in the AMI. So if I wanted an EC2 instance with just 4BG, I can't, as the AMI has an EBS volume of 8GB.

Thus the EBS volume size should be set to a size that better reflects the actual content, making it easier to create smaller EC2 instances and further increasing the spin up time for them.

Thanks.

[Rasmus Mikkelsen (rasmusnu)]

Measurements on time was done using the pending time from the EC2 metadata layer and comparing it to a timestamp taken within a script that runs on boot each time.

[Rasmus Mikkelsen (rasmusnu)]

Here's the graph from our build setup that utilizes EC2 spot instances.

Across the entire timeline there's a clear drop in the minimum amount of time it takes the EC2 instance to get online. At this time, we reduced our own AMI from 10GB to 8GB.

There was no noticeable impact when adding or removing several GBs of data from within our AMI. Nor changing the size of the EBS volume of the EC2 instance that use the AMI.