The Media Filesystem (MFS) is the database and filesystem that the TiVo uses to hold all of its useful information.
Alongside its Linux filesystem, TiVo runs a custom hybrid filesystem and database called the Media Filesystem (MFS). The MFS is where the TiVo stuffs all its recorded programming and knowledge. Here you'll find the programs appearing in your Now Playing List, databases of famous actors, your Thumbs Up/Thumbs Down show ratings, WishLists, Season Passes, messages—everything that makes your TiVo a TiVo.
The reason for using a custom filesystem is not fully known, but most people speculate it's twofold. First, it allows for very large video files to be stored safely. If you've ever turned off your computer without shutting it down, you've no doubt noticed just how long it takes to come up the next time. It's checking to make sure its filesystem is intact and nothing's out of step or just plain corrupt. With its specialized filesystem, TiVo gets around this problem and manages to boot in a reasonable amount of time, which is vital for something considered more of an entertainment system component than a computer.
Second, the MFS allows for rich metadata to be associated with media files, including Thumbs Up ratings, lists of actors, directors, genres, and so forth—everything TiVo makes available to us about the shows we're watching and TiVo, Inc. about our preferences. On the whole, TiVo's MFS is both a simple filesystem and a rich ...