The Permanent Preservation of Human Knowledge

Wayne2 writes: While there have been many attempts to preserve human knowledge in electronic format, it occurred to me that these attempts all assume that human civilization remains more or less intact. Given humanity's history of growth and collapse with knowledge repeatedly gained then lost, has anyone considered a *more* permanent solution? I realize that this could be very difficult and/or expensive depending on how long we want to preserve the information and what assumptions we make regarding posterity's ability to access it. Alternatively, are we, as a species, willing to start over if we experience a catastrophe, pandemic, etc. of significant magnitude on a global scale that derails our progress and sends us back to the dark ages or worse?