How do my store data for a really long time?

http://www.sciencedaily.com/releases/2008/04/080421133025.htm
Pergamum,introduced by above link, is a distributed network of intelligent, disk-based storage devices. It uses individual building blocks consisting of a hard drive; a small, low-power processor (like the chip in an iPhone); a flash memory card; and an ethernet port. These units, called "tomes," are connected using relatively inexpensive ethernet switches. Each unit has very low power demands and it can use disk or further storage device,e.g. holographic storage(激光全息存储).