"How did you get around the problem I mentioned in your app? Access SSH directly?"

Currently, Time Drive is just a front end to Duplicity, so it uses it to handle all of the actual backup. But to answer your question, you are correct, it uses ssh directly and avoids hard links. Rather than create a hard line like the cp/rsync strategy of BackInTime, instead duplicity creates a compressed/encrypted tar file archive. Subsequent backups are then added to the directory as encrypted diffs of the changed files. It then retrieves information about the backup by parsing the file signatures.

The result of this setup is that you can't browse the archive directly, but need to use either duplicity or a utility like Time-Drive to parse it. While I prefer this sort of scheme (since I use FTP as a redundant backup and I am not about to post unencrypted files on even a secure FTP site), I know that there are many others who do not.

"Is your app written in python?"

Yes, both Time-Drive and Duplicity are pure python (with some PyQt thrown in for the GUI).

How did you get around the problem I mentioned in your app? Access SSH directly?

I've been playing with Ruby and written my own little script. Things I came across:

1) I looked at using rsync to do all of the linking etc... for me so as to avoid SSHFS. It has a parameter like --links or --hard-links etc... and also --backup. I moved away from that though (couldn't be bothered with the experimentation ).

2) In the end I did a mixed approach. I used your suggestion of SSHFS. This was so that Ruby could create any necessary directories, and also delete any older ones as part of the cleanup my script does. This was easier than using the net-ssh lib which I was having problems with. I then use rysnc -e "ssh" to sync over normal ssh, and also an ssh command to do the "cp" hard linking.

Not an ideal solution as it's a bit mixed but it's working for me. I may well take a look at your app though if it's pure SSH. I should really try and get the net-ssh lib in Ruby working then all my problems would be solved, but given I've got it working I'm a little bored/tired of it for now. I should really have done some upfront unit tests for it too.

Is your app written in Python?

http://www.oak-tree.us/blog/index.php/science-and-technology/time-drive