RAID not always best bet
As discussed in your Sept. 9 Tech Briefing the demand for on-line storage is growing dramatically in almost every area of government. But there are only three reasons RAID would be the storage solution of choice: habit VAR sales efforts or mistaken demand for instant access. The sales certainly are not driven by realistic price/performance evaluations long-term data reliability or low-cost expansion.
The key reason for selecting RAID rather than an MO jukebox solution is the premise that the data needs to be available for instant access. However according to every industry study after 30 days 80 percent of the data that is stored is never accessed. That means that in Lt. Col. Richard L. Roach's example he has paid $2.3 million for his storage upgrade of 320G and only 64G is active data.
While it is true that RAID is the acronym for Redundant Array of Inexpensive Disks the solution is anything but inexpensive. Recently we searched key supplier World Wide Web sites for "typically" priced solutions using 40G to 50G as a price/capacity baseline. There is a tremendous cost-per-mega-byte difference between the options.
Perhaps a better solution for system administrators to insist upon is a combination of technologies that incorporate a lower-capacity RAID system at the front end for true real-time access information and a high-capacity optical jukebox for near real-time access for the remaining data. Today's new high-speed high-capacity direct-overwrite 2.6G MO drives provide 24 msec access and 4 megabyte/sec data transfer performance. The drives write data as fast as they read it so they also are good solutions for disk mirroring and on-the-fly disaster recovery. And when incorporated into jukeboxes they certainly can provide a more cost-effective solution than a 100 percent RAID approach to data storage.G.A. MarkenPresidentMarken CommunicationsSanta Clara Calif.