Every quarter the Economist runs a special technology section that never fails to enchant, and the latest version in the November 30th, 2013 edition) didn't disappoint.
A story entitled "Magnetic tape to the rescue" caught my eye, and if the purported trend to revive tape storage in the era of "big data" holds true, it may have some interesting impacts on data center energy use.
First the article notes that the growth in stored data is marching at a much faster pace than the need for compute resources, doubling every two years. Compute growth has evidently slowed from a rate of doubling every five years to something like a ten percent annual clip.
But for all the talk of solid state storage systems taking market share from spinning disks, the inexorable decline of magnetic tape systems seems to have stopped, and use of the oldest storage technology may actually begin to increase.
Mag tape systems are still used for long-term archiving of data that is very rarely accessed. Basically you store info to tape and send it off to a repository somewhere, hoping never to have a need to retrieve it.
Its an excellent medium for this use, with great data density, low cost, long life, and next to negligible energy use (not much to record it, and not much to keep the store room cool and dry). So, for storage of "cold data", it really can't be beat.
Of course there are efforts afoot to make tape storage even more attractive by increasing storage density (35 terabytes on a single cartridge!).
I do wonder if the reintroduction of tape drives in data centers might have negative consequences on overall energy use. It was always conventional wisdom that the very tight environmental requirements that are still pervasive in the industry were relics of the days of punch cards and mag tape drives - especially the very narrow tolerances for humidity.
I expect that if mag tape drives still require special environmental conditions, they'll be housed in separate rooms in efficient data center designs, so that the "factory" machines (servers, com gear, and solid state and spinning disk drives) can sweat it out on the shop floor.