Which is greener?
The tape versus disk debate has now found a new field of battle, it seems. At the Experis/EMC event in DC this week, EMC made the case that replacing tape with disk was the way to go (big surprise, that). The fellow who spoke for Hopkinton enumerated the many benefits that would accrue to using tapeless VTL disk arrays to replace "older-than-the-hills" tape technology.
I had heard it all before, and I don't buy it now.
In the Q&A phase, one smart attendee pointed out that he was trying to green his data center -- mainly to reduce power requirements. Didn't replacing tape with disk accelerate power consumption? It was a great question.
EMC's response went to cost of ownership instead of green value. I found that amusing. The response, that you save money in labor cost savings, by substituting disk for tape, while it may have some merit, is not the answer to the question that was being asked. Tape is still much greener by comparison.
I would be interested in someone telling me why this position is incorrect (if it is): does a tape library with the latest high capacity media generate more heat and consume more power than racks and racks of drives providing the same capacity and always powered on?
Also, given the findings about drive failure rates in SATA arrays, do you really reduce labor expense by substituting cheap disk for tape? I have serious doubts about this one.