I was thinking about one time, single shot backups, but encrypted wtih tarsnap. No dedup. After all, storage is cheap and this is supposed to be zuper worst case scenario stuff, so maybe I don't want to go to the trouble of reconstructing the backup. I want to know it's there. But my interest is only theoretical.
If you have a command line tool to access Glacier, I think what you can do is make an archive (with tar), encrypt it with gpg, and just use the command line tool to upload the encrypted archive. So you don't need tarsnap for that, but if you want fancy deduplicating incremental encrypted backup, that's where tarsnap shines.
Yes, but I'm already using tarsnap. Running it with "--backup-to-glacier" is easier than rolling my own. I don't want two passwords, two super duper secret keys, two online services I have to pay, ....
More or less. But I may also want to use the same machine key to perform smaller incremental backups (smaller data set), and I definitely don't want to have to print out two different keys to store in my safe. Just thinking here.