Storage vendors' emphasis on disk-based storage and backup products might cause IT pros to wonder whether the tape-based storage technologies they've relied on for years have much of a future. But recent IBM research bodes favorably for tape, although it will probably take a while for the research to come to fruition as actual products.

Earlier this month, IBM recorded a new world record in magnetic-tape data density. Researchers at IBM's Almaden Research Center were able to cram data onto a tape at a density of 6.67 billion bits per square inch, or more than 15 times the data density of the current generation of tape drives. The breakthrough in density derives from advances associated with hardware, software, and tape-coating technologies. IBM developed a more sensitive read-write head that uses giant magnetoresistive (GMR) head materials that can sense very small magnetic fields in hard-disk drives. IBM also improved tape-handling features and developed new software that can process captured data faster and more accurately than before.

Part of IBM's breakthrough came through the company's relationship with Fuji Photo Film. Fuji collaborated with IBM researchers to develop a new high-density, dual-coated particulate magnetic tape by using barium-ferrite magnetic media. Fuji also used a new coating technique, which its researchers say is more commercially viable than other systems used to create high-density magnetic tape. And according to Fuji, manufacturers can produce the new tape media by using their existing equipment.

Although commercial products based on these technical breakthroughs probably won't enter the market for another five years, IBM's Linear Tape-Open (LTO) technology now has a clear roadmap from its current capacity of 400GB per cartridge through to a capacity of 8TB of uncompressed data per cartridge, says Bruce Master, senior program manager for IBM's worldwide tape storage systems. The current generation of LTO was introduced at the end of 2004, but by next year, according to Master, LTO-4 with a capacity of 800GB will appear on the market. He anticipates that tape-cartridge capacity will double every two years or so.

At the same time, the cost per gigabyte for tape should continue to plunge. My calculations with Master over the phone indicate that the cost of 1MB of storage has dropped by a factor of 1000 from when the first generation of LTO technology was introduced in 1998.

Of course, LTO isn't the only tape-storage format in the market. Tape continues to be a fiercely competitive sector, and Master anticipates that other vendors will continue to invest in their technology and make significant capacity gains as well. The tape-storage sector will expand 8 to 10 percent a year through 2011, says Master.

This kind of spirited competition means tape should be able to retain a significant total cost of ownership (TCO) edge over competing storage approaches. As the demands for storing huge amounts of data for longer periods of time continue to mount, the need to store more information in less space will grow as well. When tape is bundled with compression capabilities, it will be able to store petabytes of information on a single data cartridge.

Even as capacities increase, however, the role for tape storage promises to become more focused over time as companies use tape primarily for archiving, business continuity, and specific data-protection applications. The good news for storage users, though, is that, with a clear development roadmap, tape clearly will play an important role in their storage strategies for a long time to come.