360 Terabytes on a piece of glass about the size of a quarter. About the only way to lose the data is to physically destroy the glass chip. Right now it's still in the development stage, but the researchers who invented it are looking for a development partner. This means, potentially, an end to tape, or pretty much any other long-term storage mediums. From the story it leads me to believe it's a ROM only storage medium, maybe like the original CD-RW that once you closed the session you could not add to the disc. Though since it's glass and laser-based writing, it may be that you could easily add to it once you filled it up.
http://money.cnn.com/2016/02/17/technology/5d-data-storage-memory-crystals/index.html?iid=ob_article_hotListpool&iid=obnetwork
http://money.cnn.com/2016/02/17/technology/5d-data-storage-memory-crystals/index.html?iid=ob_article_hotListpool&iid=obnetwork