PingFS

When Voyager was at Jupiter, communications allowed for a bitrate of roughly 115kbit/s. The distance from Earth to Jupiter is about 5AU. The current distance to Voyager is 100AU, so let's say we still have a bitrate of 1kbit/s. According to WolframAlpha, Voyager 2 is about 50000 light seconds away from us. Now you can do the math.

A video of the talk is here: http://www.confreaks.com/videos/198-rubyconf2009-worst-ideas...

My understanding is this:

It's a filesystem that stores it's data in a temporary packet. So when you ping a server to see if it's up, it sends back the data you sent so you can verify it's okay. It's implemented as a filesystem using FUSE (which allows for all kinds of user space filesystems) so the OS just uses it like a disk or network storage and so on. I believe it works by spamming out pings with the data in them, and when they come back just send them out again.

seems like it essentially keeps data stored by catching data from ICMP (ping) packets, rewrapping them in another ping packet and shoving them back on the network.

Think of it kind of like network RAM, the data isn't stored anywhere persay and if either host fails to bounce back the payload the data is lost since it wasn't stored on any single machine and only kept alive in limbo.

As oakwhiz pointed out, this is conceptually similar to delay-line memory [1]. At least it doesn't require 100○ F mercury.

[1] http://en.wikipedia.org/wiki/Delay_line_memory