• United States
by Dave Dupont, special to Network World

UDO boosts storage capacity

Sep 27, 20043 mins
Backup and Recovery

Regulatory requirements such as Sarbanes-Oxley and the Health Insurance Portability and Accountability Act, in conjunction with the ever-increasing threat of litigation and the desire to derive maximum value from information assets, are compelling organizations to develop robust archival storage strategies. A new technology called Ultra Density Optical promises the capacity, scalability and longevity that corporations require. UDO drives typically will be installed in optical libraries connected to networks.

UDO was designed to meet the demands of archival storage applications by offering higher media capacity than traditional optical storage. Capacity of DVD technology maxes out at 9.4G bytes, whereas the first generation of UDO drives and media can store 30G bytes. 60G- and 120G-byte versions are planned.

The limiting factor in optical capacity is the size of the “spot” produced by the recording laser. Traditional optical storage devices, including CD, DVD and magneto optical, utilize red or infrared laser technology. But UDO drives use blue lasers, which feature a shorter wavelength (405 nanometers) than red lasers (780 nanometers for CDs and 650 nanometers in DVDs). The combination of the shorter wavelength and new optics let blue lasers focus on a smaller spot. And more spots in a given area means more data in that area.

UDO drives record data using an 8K-byte sector size to maximize media capacity and performance. In a process known as phase change recording, the drives write data by heating a spot on the media recording layer with a blue laser and changing it from a crystalline to an amorphous state, recording a data mark. The same laser, set at a lower intensity, is used to read the media.

Just like other types of optical media, UDO is available in rewritable and write once formats. Because both media types are non-contact, non-magnetic, data recorded on UDO does not degrade with use, is not sensitive to exposure to magnetic fields, and accommodates a wider range of environmental temperature and humidity conditions than do current optical drive technology. In tests, UDO media was shown to have a life expectancy of more than 50 years when stored in a typical office environment.

The International Organization for Standardization and International Electrotechnical Committee ratified the ISO/IEC 17345 standard for 30G-byte UDO media in December.

Major systems vendors support UDO, and more than 30 independent software vendors offer UDO drives and libraries for a range of applications, including data life-cycle management, direct access archival, hierarchical storage management and industry-specific uses.

UDO is the only blue laser optical storage technology approved by the ISO and European Computer Manufacturers Association. Together with a standard for volume and file structure, ISO/IEC 17345 provides for full data interchange between UDO optical disk drives.

DuPont is vice president of sales and marketing at Plasmon. He can be reached at