So we all know that books last a long while right? How about its modern equivalent the CD, DVD or Hard disc? Most of us commit a larg part of our life to digital storage these days and don't even spare a thought for how long this digital memory will last. In the case of hard discs, 5 years might be your limit.This then is the classic problem with digital storage - longevity. All other problems vanish into insignificance when considering the persistence of storage. Our current best hope is optical media, the best of which are believed to be good for around 50 years. (interesting to think that our CD and DVD collections are more temporary than we are!)Recently, a team from University of California Santa Cruz have come up with a system called Pergamum which uses regular hard drives to store data for a projected 1000 years. The system, called Pergamum, uses a large number of inexpensive discs, most of which are spun down. Persistence is created by using multiple slow sync mirrors & stripes. Clever caching and an even cleverer data distribution protocol ensures that data reads, writes, rebuilds and other operations make the least demand possible on the hardware whilst continuing to be power efficient.As an example, it's estimated that a 10Petabyte system would consume only around £20 of power per year including HVAC requirements and would be capcble of maintaining that 10PB for arount 1000 years before a data loss occurred. Pretty good methinks!More on the announcement in this tgdaily article.