I'm looking at this:

http://www.tarsnap.com/

HN has mentioned this several times in the past. I'm now looking at the prior comments about this.

tarsnap is awesome, but it's in no way a replacement for dropbox - their use cases and scenarios where you can use them are entirely different.

If anything is overpriced, tarsnap is -- or was, last time I compared prices. Also picodollars are a bit opaque.

I really wanted to use it and hoped it'd come out reasonably compared to alternatives, but I actually found none except buying a hard disk + raspberry pi myself and hosting it at a friend's place. That was cheaper by about a factor 2, which (at 3TB data) was too much to ignore for my student budget. This was about two years ago though.

That's probably the first time anyone's ever complained about tarsnap being too expensive, honestly. 'tptacek & 'patio11 bang on a lot about it being too cheap, and they're right. tarsnap costs a pretty minimal amount over the underlying S3 storage, but I'm sure if you don't really care about 99.999999999% durability a hard drive on a pi is great too.

Tarsnap's great but it's a backup service not a sync service and is very unsuited for use as a sync service.

Resilio Sync [1] (Formerly BitTorrent Sync) has worked well for me.

[1] https://getsync.com/individuals/

Indeed. Resilio Sync is a peer to peer synchronization tool, so data is not stored in the cloud. If you want a permanent cloud peer, Resilio Sync has the option of creating encrypted read-only secrets that you can use on a cloud peer. Such a peer will participate in the swarm, but will only see ciphertext data.

The application does not ask or require root access. And they support Linux and FreeBSD as well.

SyncThing should also be mentioned. However, if you want to share folders to other people as well, Resilio Sync seems to be the best option.

is a part of a toolbox you could possibly build a dropbox alternative on top of. It's not a file-sync tool out-of-the-box, and probably never will be.