The complexity necessary for long-term preservation of digital records contributes to the potential for failure. Consider the vulnerable points, colloquially known as a chain of weak links:
Gordon Hoke on KM world
Removable media—There is no way to assess the longevity of removable media, including tape and laser-written disks (CD, DVD, Blu-ray, WORM, etc.). There are too many variables. The standard way of testing media is “accelerated aging,” but only the future will prove its accuracy. There are no standards for quality, and it is difficult to impossible to consistently identify the materials and manufacturing processes that produced a shipment of disks. Controlled temperature and humidity affect the stability of a disk’s substrate and dyes, but storage environment is only half a disk’s life cycle. Even for a disk made of high-quality materials, who can verify the conditions and duration under which the disk was transported and warehoused before use?
Hardware obsolescence is obvious and visible to all who have reached adulthood. Floppy disk drives (5.25-in. or 3.5-in.) are difficult to find, to say nothing of players for ZIP, Jazz and other proprietary format media. In 1991, Sony advertised a 12-in. optical disk guaranteed to last 99 years. While the verity of that claim will be revealed in 2090, not even museums are likely to have a compatible disk player.
As operating systems evolve, they have limited compatibility with their ancestors. Can a PC running Windows 7 read files created under CP/M? Can today’s IBM Power System OS consistently extract files written on a s/38 from 1979 or a system/3 from 1969?
Application software becomes obsolete as well. Consider the boneyard of former market leaders: VisiCalc, WordStar, Wang word processing and countless others. Microsoft stopped supporting Office 97 about 10 years after its release.
Output drivers—Retrieving old records also depends on being able to display and/or print content. Even with legacy CPUs, OSes and application software, the period monitors, printers and the software that drives them may be unavailable or inoperable.
Encryption and password protection—Long-lived records, including health records, often require security and privacy protection. Maintenance of passwords and decryption capabilities loom as additional impediments to the retrieval of old records.
jhagmann - 5. Okt, 07:55
