Technology thwarts RAID data loss

By Sonia Lelii  |  Posted 2000-12-04

Land-5 Corp. has developed a software-based technology that gives RAID storage systems the ability to sustain multiple drive failures without risking data loss.

Based on 10 years of R&D, Land-5s RAIDn technology lets IT managers select how many disk drive failures a storage subsystem can sustain without risking data loss.

"The last enhancement to RAID was 15 years ago," said Kris Land, founder and chief technology officer of Land-5, in San Diego. "Yet every single storage system on the planet runs on 15-year-old technology. It is about time to update it."

Thus far, RAID Level 1+5, which offers both mirroring and parity, can handle up to three disk drive failures.

"For the first time, you have the ability on a drive-per-drive basis to select the level of insurance you want on your RAID box," Land said. "You get to choose the level you want by simply choosing that number."

One systems integrator believes Land-5 is raising the bar for RAID technology.

"This is going to change the way the world does [RAID]," said Lee Elizer, president and CEO of DataThink Inc., in Boulder, Colo. "RAIDn needs some evangelizing, but this is the RAID of the future."

Land-5 officials said they expect to begin beta tests on RAIDn within two weeks.

Currently, RAIDn technology has been implemented in Linux operating system software. Land said it will also be available in firmware for hardware controllers in 30 to 60 days, and it will be implemented in an application-specific integrated circuit in about 90 days.

One of the biggest challenges customers face with RAID has been deciding which level to choose. If customers wanted higher reliability, they sacrificed cost, capacity and performance. If customers wanted higher performance, the trade-off was lower reliability.

For instance, RAID 0, which stripes data across drives, offers maximum performance capacity, but reliability is sacrificed because if one drive is lost, data is lost.

RAID 1, which also stripes data across drives, offers higher reliability because it can handle at least one drive loss, but it gives lower performance.

"This is going to change the way people think," Land said. "Now you only have to ask two questions: What are the total number of drives you want to use, and what is the total level of redundancy you want on them?"

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