For over 30 years I have heard that tape is dead or dying, but after all of these years it still remains a vital part of most data centers. Was the demise of tape wishful thinking (EMC you know who I’m talking about) or is it really a dead technology?
The cost of disk storage has dropped dramatically over the years, but try as people might they can’t get rid of their tape.
There are several reasons why this is the case – The average life expectancy of a disk drive is 3-5 years which means that data written to disk will need to be migrated to a newer device as equipment is retired. Migration might not be too painful (it usually is) but it takes time to migrate, it takes people to write the scripts and verify the results, you might want to clean up the data by examining what you have and deleting extraneous or dead data, and why do you keep writing ancient data to shiny new devices? The average life expectancy of a tape cartridge is 15-30 years. We could posit that once data is written to tape it will probably never need to migrated unless it contains some type of regulated data that must be retained, but I believe most enterprises would simply keep the cartridge in the vault and hope no one ever asked them to produce anything from it.
Obviously there are different types of data – databases; business records; application data; tif and gifs; MP3s; and, a variety of other unstructured data. While most businesses don’t keep MP3s and GIFS as a standard part of their operations, their employees do and they always seem to end up on that expensive enterprise disk. Only a fraction of this data is actually business critical.
A huge problem most data centers face is the limited amount of electricity and cooling available to them. While new technologies have evolved to get the most bang for the buck including denser capacities, faster processors, multi-core CPUs, and virtualization software the truth of the matter is there are only so many KWs available and they are used to both run equipment and the Air Conditioning. While you can expand your floorspace you can rarely get more power to your building.
So why tape? It has a longer shelf life, it lowers the administrative workload, and once written requires little power and cooling to maintain.
In all, while tape is an ancient technology it provides a better platform to deal with the 21st century problems facing Data Center managers.