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|At a Glance: Asaca's TeraCart PD Optical Storage|
For more than a decade, efforts have been underway to improve laser technology and to pack more data onto 120mm disks than was possible with red-laser technology. A development consortium, including Hitachi, Matsushita Electronics, Philips, Samsung, Sony and others, discovered that by using narrower, blue-violet laser beams, with their shorter wavelength, they could squeeze 23.3GB of data on each 120mm disk and maintain backward-read-compatibility with red-laser 120mm discs. The new TeraCart PD libraries offer write once, read many (WORM) technology and rewritable recording formats, and deploy a bare-media strategy that eliminates the need for the media cartridge.
An interesting feature of TeraCart PD is its flexible direct-attached storage (DAS), network-attached storage (NAS) or storage area network (SAN) connectivity. The library can be direct-attached to a system via SCSI; attached to a SAN via multiport Fibre Channel host bus adapters; or attached to a LAN using multiport Gigabit Ethernet. When network-attached, the library is accessed as a mapped drive or mount point using the NAS protocols CIFS and NFS. Additionally, TeraCart can be configured as up to four virtual libraries and shared based on user/group permissions.
"This allows our customers to partition the library and share the system among different groups," says Chuck Larabie, VP of sales and marketing at Asaca/ShibaSoku. "The partitions add another layer of security to prevent people from accessing data that doesn't belong to them."
WORM media will last considerably longer than tape because of the durable nature of the disk and the non-abrasive laser-writing process. Magnetic tape is typically stated to have a lifetime of approximately 30 years, contingent upon narrow usage, as well as stringent temperature and humidity conditions. The new Sony disk media is expected to last 50 years or longer, and has much more lenient storage environment specifications.
TeraCart PD brings optical storage into the competitive range of tape with a cost of approximately $3.50/GB. Some hard disk-based libraries are beginning to approach this range, but most are still priced higher. The roadmap for PDDT includes 50GB and 100GB single-sided disc capacities and, later, 200GB double-sided discs.
One possible concern over deploying TeraCart PD is the industry battle over blue-laser standards. The competing industry camp is led by Toshiba and NEC, and supports a proposed HD DVD standard with similar benefits.
This was first published in February 2005