Comment 20 for bug 1039511

I understand that using Amazon's feature of moving data back and forth between S3 and Glacier, it would be possible to backup data to S3 and Glacier following the general principles below:

1.) We would backup the data to S3
2.) Most (>90%) of the data would reside in Glacier (will be moved there using some rules)
3.) Few files (<10% will reside in S3) so as to not confuse duplicity when backing up
4.) If a restore is ever needed, data is restored from Glacier to S3 and we'll then use duplicity to restore from S3 (possibly using a different restore path from the original one used for backing up to S3)

I'm confused mostly about points 2 and 3, that is:

* What rules should we use to move what files to Glacier?
* What are the files required to reside on S3 so as to not confuse duplicity when doing new backups (as in duplicity must believe the full backup is there, even though >90% of the files have actually been moved to Glacier)?