How does it work?

For a quick answer see the one page summary. For more details, read the architecture description and Tahoe-LAFS documentation.

What are the risks of using Tahoe-LAFS?

Generic known issues (not I2P specific) are:

• Potential unauthorized access by JavaScript in unrelated files
• Potential disclosure of file through embedded hyperlinks or JavaScript in that file
• Command-line arguments are leaked to other local users
• Capabilities may be leaked to web browser phishing filter servers

See the known issues list from the upstream project for details and ways to mitigate.

Are stored files encrypted? What algorithms are used?

Yes, everything is encrypted. For details see the file encoding specifications.

"UnrecoverableFileError: the directory (or mutable file) could not be retrieved, because there were insufficient good shares."

Did you just start your node? Wait until you're connected to a few nodes, which takes a minute or two. You can see how many nodes you are connected to on http://127.0.0.1:3456/#grid

How do I rebalance shares?

You can't automatically right now. There is a rebalance workaround and ticket 699.

My question isn't covered in this FAQ!

Check the official site of Tahoe-LAFS, their FAQ or visit our IRC channel #tahoe-lafs on I2P.