Change is the plan for optical storage
- By Larry Stevens
- Apr 21, 2003
Ever since government agencies began scanning paper records and converting them into digital files, magneto-optic disks, also called platters, have been the storage media of choice, and for good reason. The platters are rugged, and their storage life, though not yet tested in the real world, is estimated at 25 years or more.
Perhaps the disks' most valuable feature is the write-once read-many (WORM) capability, which ensures the authenticity of images and allows agencies to use the disks to replace microfiche for archival purposes. Despite this long and happy relationship between imaging and magneto-optic disks, there are some changes in store.
That's in part because the most common format in use today — the 5.25-inch disk technology built by Sony Electronics Inc. — is reaching the end of its road. Industry word is that Sony plans to phase out the disks, although the company has not officially said so. The prospect of no more magnet0-optic disks might have caused some anxiety among imaging users a few years ago when there were few alternatives to WORM optical disks. Now, however, they might have the opposite problem to fret about — too many options.
In the optical space, two heirs to the magneto-optic crown are set to debut this summer: Plasmon's Ultra Density Optical (UDO) and Sony's blue laser high-capacity optical format. Both products use a short-wavelength violet laser that allows a much higher storage density than current laser technology.
For records managers who can embrace the notion that imaging doesn't have to equal optical disks, there are other new WORM choices as well. One option is using hard drive-based systems such as EMC Corp.'s Centera, which offers the speed and performance of hard disks with the document integrity of WORM. The other is WORM tape, first introduced by Storage Technology Corp. but now available in a midrange format from Sony.
Despite the sudden bounty of WORM storage options, many agencies with document-imaging systems still believe the old-time magneto-optic religion is good enough for them. "MO gives our users a warm and fuzzy feeling because we've been using it for years and we know it's reliable, secure and can't be tampered with," said Thomas James, chief information officer at the Miami-Dade County Clerk of Courts. He adds that the proven permanence of the disks is important, because in some criminal cases, the court has to maintain records for 75 years.
The clerk's office has deployed an enterprise content management tool from FileNet Corp. to automate its traffic court system. Every piece of official paper that comes into the court — items as varied as court filings and tickets — is scanned into the system. The office currently stores its images on older 12-inch magneto-optic platters but is moving the files to Sony's 5.25-inch format.
When James first proposed the storage upgrade, optical laser had not been announced. It's still not available, so he doesn't feel he needs to consider it. He, along with most experts, is certain that the standard magnet0-optic disks will be available and supported for many years.
FileNet's product marketing manager Jerry Bower agreed. "We expect to have these disks for at least the next five to seven years and probably much longer," he said.
Still, assuming Plasmon's UDO is shipped as promised and an agency plans to purchase an optical storage system later this year, the new technology offers a clear road map to higher capacity, while the older magnet0-optic disk has already reached its upper limit. The initial UDO release will be a 30G platter that costs about $90. In 2005 or 2006, Plasmon expects to release a 60G version, and by 2008 or 2009, a 120G disk.
"From the start, UDO will have at least a three-times price advantage over the older technology," said Britt Terry, UDO product manager at Plasmon.
James Riggs, project manager with the Army Personnel Electronic Record Management System project, agreed that agencies considering magneto-optic storage should look closely at UDO. PERMS relies on a custom-built imaging system that is used by 400 to 600 records clerks. The system stores personnel information on older 12-inch magneto-optic disks, microfiche and other media.
However, the Army is about to allow its user base of 1.2 million soldiers to access their own records via a Web interface. "To store all those records online, we need as much capacity as we can get," Riggs said. To that end, he said the Army plans to buy a UDO-based system when it is available, one that will store between 15 and 30 terabytes of data.
Sony recently began demonstrating what is effectively the successor to its current 5.25-inch disks. The new format — like Plasmon's UDO — will not be backward compatible with the previous magneto- optic drives and media. The initial Sony product will offer 23.3G of capacity per disk. Second-generation media, expected by 2005, will store 50G per disk, and third-generation media (no projected date) will store 100G.
The future of optical laser technology is impressive, but the one for hard drives is even better, according to Jack Scott, managing partner at Evaluator Group Inc. "MO is now beginning to fall behind in the WORM data-density wars," he said. "A magnetic disk has got several times more bits per square inch than MO."
Hard disks also enjoy the important advantage of always being online, enabling them to deliver extremely fast file access. Tapes and even optical disks, on the other hand, must often be loaded by a library or jukebox's robotic arm onto a drive to read and write data, adding seconds or more to many operations.
Drawing much of the attention on the hard disk front is EMC's Centera Content Addressed Storage system, introduced last year and designed for storing information, such as images, that will not change. It is an integrated hardware and software system that preserves records in a nonrewritable, nonerasable format.
Wolfgang Schlichting, research manager for removable storage at IDC, said EMC will have to overcome the reluctance of some agencies to bet on a technology that's only available from one company. "EMC is very large and stable. But the question has to be asked if they will continue to support Centera," he said.
Sean Lanagan, director of emerging markets in EMC's Centera division, said early sales successes indicate strong acceptance of the technology. He said the company has a Centera installed base of more than 2 petabytes. He also said that Centera meets or beats the protection and security requirements of Defense Department standard 5015.2.
Perhaps most significant for document imaging users is that FileNet is among numerous companies with software that supports Centera.
In general, storage is the least problematic component of a document-imaging system. However, when a system reaches capacity, decisions have to be made. Because of the longevity of storage systems, making the right choice is extremely important.
Stevens is a freelance journalist who has written about information technology since 1982.