The Economics of Tape

In recent posts, I’ve mentioned tape’s relatively low cost as one advantage of this data storage medium. Now, I think it’s time to take a closer look at the economics of tape.

First, what do we really mean by “relatively low cost?” Of course, the answer depends on the variables you factor into your cost comparison. Storage timeline, data type, media specs, energy costs and many more assumptions can affect the result. Even accounting for differences in these variables, though, the results are clear: tape is more cost-effective than disk for long-term storage and archiving.

• A study by The Clipper Group found that for long-term storage, the average tape-based solution costs 1/15 of the average disk-based solution. The same analysis found that the average disk-based solution uses 238 times the energy of the average tape-based solution, and its energy costs exceed the entire TCO of tape.
•  An analysis by BackupWorks.com calculated the cost of a tape backup solution to be about ¼ that of a disk backup solution.
• The cost per megabyte of storage has been cited at less than half a cent for tape and at least 2.5 cents for disk.

Tape costs less than disk in terms of energy (to run the IT infrastructure and cool the data center), floor space, equipment, media and maintenance—especially over the long term. These are the facts, and they are (more or less) undisputed.

Granted, few data backup, recovery and storage solutions are based purely on disk or tape. More commonly, a balanced enterprise storage strategy incorporates both. So, clearly, direct costs are not the only consideration when it comes to choosing storage media. Organizations also have to consider the business costs of meeting their service level agreements. The question organizations need to ask is this: How can we most cost-effectively meet the service level requirements of the business?

For some business needs and data segments, the need to achieve rapid recovery time objectives will outweigh the cost benefits of tape. But for other business requirements and data segments—specifically for long-term storage and archiving, as we’ve said—intelligently incorporating tape into your enterprise storage approach can help minimize total cost of ownership. And that’s a strategy you can take to the bank.