[touchofevil]

The best thing to do is probably to buy an NAS, seed it with your 17TB of files and then colocation it at a colo facility or a friend's house and then use some sort of one way sync utility (rsync, rclone, carbon copy cloner, bittorrent sync, etc) to update the remote NAS as you add/delete files to the source.

[ChuckMcM]

This is the way I would go took, although with two NAS boxes. One local and a similarly sized one off site. Then you backup to the local one and you sync the state to the remote one.

Lose data locally, restore from local NAS

Lose data on local NAS, restore from remote NAS

Lose data on remote NAS, restore from local NAS