Delta backups done against full rather than incrementals

[rdelcorro]

Hi @ddebeau I am seeing in my aws console that the incrementals created are based on the full rather than on previews incremental.

If you look at my backups, they are getting bigger and bigger duplicating a lot of data. I can't create a new full as it needs to be stored for 6 months due to deep archive constraints. I am open to create a PR to solve this but I wanted your opinion on the subject.

This affects:

• Backups: They need to look into the latest incremental and use that as a base
• Restores: They need to restore the full and all the chain of incrementals up to the point where the user specifies in time

The savings would be massive across time

Thanks

[ddebeau]

I would support a PR that adds true incremental backup support. The backup object should support it. Just the backup and restore logic would need to be changed.

The feature would be a pretty big undertaking. Let me know if you have any questions or run into any issues creating new tests!

[rdelcorro]

Finally I completed this work! PR: #75