You talk about disk and tape for DR. What about optical alternatives such as MO or DVD? The cost of these technologies is very inexpensive and the reliability very high. Like disk, the data can be restored or read directly from the media. There is no wear on the media so constant replacement isn't necessary. There are many very large companies who bet their data on this technology. Is this not a viable solution?
It's not that they are not viable. There are a few issues with optical solutions though, the most important of which is that they are too expensive. MO and DVD are still much more than IDE disk or tape. MO is many times more expensive than tape, sometimes as high as 30x. Even the cheapest DVD solutions are five times the cost of tape and slightly more expensive than disk. And, don't forget that unlike MO, DVD and tape, disk is both the media and the drive, driving up per MB cost for disk even higher). This difference in price might be easy to overcome for small environments, as they do not need to buy as much media as a large environment. However, a 2X or 3X difference in media price means hundreds of thousands of dollars to large companies.
MO is a fine format but it has a very small market. Therefore it will continue to remain expensive, as its only market is long term data storage in automated environments. It is almost never sold in the consumer market. If it were, its price point would come way down due to volume. As to DVD-R, DVD-RW, DVD+R, DVD+RW and DVD-RAM, well...get back to me when there's a clear winner in that market or when the compatibility between different manufacturers is higher than 80% (quoting a recent Business Week article).
Except for the consumer market, DVD is not being marketed as a day-to-day backup solution. Tape is MUCH cheaper and easier to use in large environments. DVD would be perfect for long term archive though -- if I could count on the format that I choose being here in 30 years. Hopefully in a few years a clear winner will appear or these various formats will all be available on all drives. When that happens, I can see more companies starting to put their long-term archives on DVD.
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