Yeah, I've been through all this too. Sounds like you want something beyond "ec2-bundle-instance" which will bundle your running instance but won't snapshot the VM from "underneath" as it's running (EBS snapshots can do that though).
Sort of. What I'd really like is a ec2-bundle-instance that works near instantly. As I understand it amazon copies our AMIs around their clusters anyways - but insists on mounting them read-only.
I'd like a flag to my ec2-run-instances that causes the AMI image to be mounted as read/write. Make the i/o dog slow if you must (it already is, anyways) but let me work directly on the image and make sure my changes persist across reboots for this particular instance. That requires them to make a copy my AMI-file on their server for that particular instance - so bill me extra, thanks.
With those mechanics in place I'd imagine an equivalent to ec2-bundle-instance that works near instantly on such r/w-AMIs would be possible. It'd only have to copy the modified image back to s3.
The take-home would be that we get a way to perform and test (hence the reboot) AMI-changes much more quickly than is possible now.
I think ec2-bundle-instance does something much like what you're asking for.
EC2 VMs are not mounted read-only. They are reconstructed from S3 and mounted read/write as a local file on the Xen node.
The changes to this file (your instance's storage) are saved across reboots when you type 'reboot' or use the external ec2-reboot-instances command.
It's just that the terminate operation does not copy the changed file back to replace the AMI that was launched (it would be quite limiting if it did that).
ec2-bundle-instance is a program that will bundle a running instance into a new AMI upon its next reboot. So it requires a reboot and is not like a live lvm-snapshot which is what you will get from EBS snapshots.
Sort of. What I'd really like is a ec2-bundle-instance that works near instantly. As I understand it amazon copies our AMIs around their clusters anyways - but insists on mounting them read-only.
I'd like a flag to my ec2-run-instances that causes the AMI image to be mounted as read/write. Make the i/o dog slow if you must (it already is, anyways) but let me work directly on the image and make sure my changes persist across reboots for this particular instance. That requires them to make a copy my AMI-file on their server for that particular instance - so bill me extra, thanks.
With those mechanics in place I'd imagine an equivalent to ec2-bundle-instance that works near instantly on such r/w-AMIs would be possible. It'd only have to copy the modified image back to s3.
The take-home would be that we get a way to perform and test (hence the reboot) AMI-changes much more quickly than is possible now.