The RAID market has continued to grow at an impressive rate, despite the relative lack of new developments in the technology itself. According to an IDC study, external RAID continues to account for more than 90% of the entire external disk storage systems market and is growing 8.9% each year. Most of that growth is in existing permutations of RAID, but there are a few new developments to keep an eye on.
"I don't think you'll find anything new and startling about RAID technology itself," said Jim Porter, president of Disk Trend and an independent analyst in the storage industry. Porter mentioned the appearance of small business and consumer RAID products as an exception.
Similarly, John Webster of Data Mobility Group opined that the largest trend was continued movement to commoditization and ever smaller form factors. In particular, Webster singled out Broadcom's Raidcore "RAID-on-a-chip" as an example of this trend.
And there are other developments in RAID of late. A few months ago, the Storage Networking Industry Association (SNIA) announced the approval of the Common Redundant Array of Independent Disks (RAID) Disk Data Format (DDF) architecture. Designed by the DDF Technical Working Group (TWG), the Common RAID DDF architecture aims to provide a standard method for storing RAID configuration information on physical disks, thus enabling interoperability between different RAID suppliers.
According to SNIA, the standard aims to help end users faced with the common task of migrating data from one RAID product to another. By standardizing configuration information in a common format, it is hoped the DDF architecture will improve RAID interoperability, ultimately providing increased choice and flexibility for end users.
Beyond that development, Webster sees one more industry development that violates the ho-hum, business-as-usual norm of the RAID world.
Out of the vault of discarded ideas, Adaptec has reinvigorated the seldom if ever used concept of RAID-6 (a RAID arrangement similar to RAID-5 but with a second parity scheme distributed across different drives to provide extremely high fault- and drive-failure tolerance).
"Depending on the exact configuration and how well it performs, other RAID schemes can leave end users vulnerable if they lose a second drive while they are in the midst of rebuilding from an earlier drive failure," Webster said. The Adaptec approach addresses this dual-drive failure problem, he said.
"Typically, this isn't an issue until you get into long rebuild times and lots of data -- then it can become a real issue," he added.
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About the author: Alan Earls is a freelance writer in Franklin, Mass.