IT Management

Tape: A Collapsing Star

5 Pages

When a star is born, the mass of the star determines how long it will live, ranging from millions to trillions of years.

Magnetic tape for data storage began life in 1951 and was used as a primary recording media by some until the ’70s. The continuous use of tape caused a buildup of market share over other tenable, long-term storage alternatives. But as the storage market universe continued to expand, other storage stars were created. The star power of tape is now fading; in an astronomical sense, it has exhausted its supply of market fuel, expanded its range as a red giant, and is now rapidly collapsing as a white dwarf to someday become a black hole in our memory.

For today, though, even a white dwarf has value. With minor exceptions, the value of tape shines only for the large enterprise. For the non-enterprise-class market, distance and portability are the only star qualities tape has left.

The demise of tape won’t be a big bang that results in a black hole through some instantaneous event. Instead, tape will die because it can’t follow or match current market conditions and requirements. Problems that limit tape’s popularity include mislabeling, labels that fall off, media failures, transport failures, library failures, media server failures, slow performance, risk of loss or theft, and the high cost of replacing, adding, or re-mastering tape for use by new generations. For all those reasons, users will simply stop writing data to tape; they’ll opt for disk instead. Every stronghold of value that tape once held has been supplanted by disk. Protection, performance, reliability, energy conservation, management, and cost all favor disk.

When Tape Made Sense

Cave art remains a hieroglyphic-written history that’s survived some 40,000 years—surpassing anything we know about data retention even today. You simply can’t beat data survivability when it’s etched in stone.

According to the University of California-Berkley, from 40,000 years ago until the year 2000, all recorded data represented a total of 2.7 exabytes. Tape could function well in that era. However, IDC now estimates that roughly 487 exabytes were added to the digital universe in 2008. IDC further estimates that five times that number, or 2.5 zetabytes, will be captured by 2012. Because not all data needs to be recorded, the total amount of disk storage capacity shipped is estimated to reach 110 exabytes by 2012. The sheer size exceeds tape’s ability to reasonably, reliably, and economically store, manage, and retrieve data.

Gartner estimates that 15 percent of all backups fail. Additionally, 10 to 50 percent of all subsequent restores from tape fail, depending on the elapsed time since the backup occurred. Restoring data from tape older than five years fails 40 to 50 percent of the time. Much of this goes unnoticed. Both Gartner and Storage Magazine report that some 34 percent of companies never test a restore from tape. Of those that do test, 77 percent experienced failures in their tape backups.

The patterns are clear. Data is growing at rates hard to conceive. Administration of the infrastructure to keep up with data growth is challenging. The management of disk to house all the data isn’t trivial, but managing disk is easier than managing tape.

Restoring from tape is unreliable in the best of conditions. When a restore from tape does work, the performance of the restore is poor. A failed restore or slow performance of a restore can spell disaster if the failure is part of a major business application’s data loss. Boston Computing Network found that seven out of 10 small firms that experience a major data loss are out of business in a year—and that assumes they’ve completed a backup and have the option of a restore. Ironically, backups to tape frequently aren’t completed in the course of a defined backup window. Without a timely backup, a restore is of little or no value.

5 Pages