Tape storage of information sometimes has an image of being out-dated, outmoded and out-performed by disk storage. That’s true enough – in the living room of your home, where audio cassettes and the VHS system for video cassettes are now antiques compared to CDs, DVDs and Blu-ray media. However, a living room is not a data centre. Professional organisations that need to store and restore large volumes of data daily have a list of criteria by which they judge their backup media. Cost to acquire, cost to operate, whether or not their brethren in the industry use it, reliability and security are some of the main ones. Tape for professional use has some surprises for anyone still thinking “living room”.
Tape storage capability is less expensive to acquire than disk storage capability. It’s also less expensive to increase incrementally, and tape storage systems consume less energy and cost less to operate than disk. In a technical brief on the subject “Debunking Five Myths About Tape Storage”, internet.com cites findings by Data Mobility Group that disk systems were over 11 times more expensive than comparable tape systems, taking into account initial system purchase and operations costs over 7 years. The same report includes a further statistic that at the end of 2010 almost half of all the date in the world was stored on tape.
As for reliability, the Oracle Company is cited in the report as assessing the bit error rate for its tape storage products as being 4 million times better than enterprise disk. If tape storage systems also allowed for random access, there would be little to stop them taking over in data centres. However, as they don’t but disk storage systems do, disk storage has a place in professional storage solutions, despite being more expensive, holding less data and providing less in the way of data encryption. That’s right – tape systems do it better with encryption built into the tape drive that still records more data faster than comparable disk drives. Maybe disk drive companies should start worrying about their future more than tape storage companies.