Fedora S3 Backed AMIs

Garrett Holmstrom gholms at fedoraproject.org
Thu Jul 28 16:42:57 UTC 2011

On 2011-07-28 8:36, Tim Flink wrote:
> As I'm learning more about EC2 and AMIs, I'm wondering what the plans
> are for Fedora S3 backed AMIs.
> If I'm understanding correctly, an S3 backed AMI has no persistent
> storage - once the instance is rebooted, all changes are effectively
> reverted. This would mean that applying updates to an S3 backed AMI
> would be a questionable process and any updates requiring a reboot
> would be impossible.

Instance storage of this sort does not go away when instances are merely 
rebooted.  It is only destroyed at instance termination time.

> Are we planning to release S3 AMIs on a regular basis or are we
> expecting users to use the S3 AMIs to build their own images and take
> on the responsibility of updating those images on their own? Or are we
> focusing on the EBS backed AMIs that do have persistent storage?

Creating Fedora respins midway through a release consumes time and 
resources that, given our difficulty with the F15 images alone, we 
appear to lack.

Building updates into images also calls GPL compliance into question, as 
updates that are superseded by newer updates get removed from mirrors 
and eventually garbage-collected by koji.  This is not the case for 
packages in the release repository, which stick around forever, or the 
Fedora Unity respins, which provide source media alongside the binary media.

I wouldn't be too concerned about supplying people with updated cloud 
images; they are really only a baseline that people can respin for 
themselves and others as they wish.  People who wish to use EC2 merely 
as a pay-per-hour VPS provider can use either type of instance and keep 
it up to date via the usual channels like they are used to doing 
elsewhere.  People who are running cloud applications have designed 
their applications such that individual instances are unimportant and 
replaceable.  In those cases it is frequently easier to simply terminate 
out-of-date instances and replace them with new instances from fresh 
system images that cloud application writers already create as their 
applications evolve.

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