Many people, realizing their old audio and video tapes have become obsolete, have paid to have information transferred to CD or DVD. The question is, how long before that storage medium becomes outdated and how reliable is the medium itself? Those are the questions addressed earlier this year by reporter David Pogue, in a segment on CBS Sunday Morning, Should You Worry About Data Rot?
What is Data Rot?
Data rot, also known as bit rot, bit decay, or data decay is a computing term used to describe degradation or decay of the medium (tapes, hard drives, CD/DVD, etc.) on which information is stored. The term also includes obsolete equipment (hardware and software), and both issues can affect access to information. This is a significant problem for genealogists who have so much at stake but may lack the expertise or financial means to keep up with the latest technology. For the average computer user, there are three primary areas of concern: media decay; outdated technology, and information preservation.
Media Decay
Storage media such as hard drives, CDs, DVDs, and tapes can become corrupt or damaged over time, resulting in a loss of data. The average lifespan of most media is 5-10 years, depending on where and how it is stored. Such things as temperature, humidity, and exposure to light can affect the actual material on which data is stored, often resulting in a permanent loss of information. Magnetic tape can become glued to itself, resulting in a loss of data when peeled apart. VHS it is said, holds up a little better, so long as you have equipment to play it, but can still be damaged or worn out.
Computer hard drives are said to last only about five years, and that includes those nifty 500 gigabyte external hard drives many people rely on for data backup. And unlike the professional music CDs sold in stores, burned CDs—those used to store information at home—may last only two to five years, depending on the quality of the CD. The lifespan of a DVD is said to be anywhere from 5 to 100 years—that's quite a range. How do we know which DVD will hold up for 100 years . . . and . . . what systems will be around to read them 100 years from now? So the issue of media decay is significant.
Outdated Technology
As hardware and software systems change over time, the media supported by those systems can become outdated and, thereby, unreadable. A classic example of obsolete equipment is the 8-track tape player—maybe because that medium was so short-lived. New technologies are constantly emerging, and much of it a simple business decision. How better to market a new product than to make the old one obsolete? But it's progress and everyone benefits, so long as people recognize the lifespan of their purchases and plan accordingly. The need to upgrade systems and migrate data is a fact of life, and the more important the information, the more urgent and important this becomes.
"I find family information to be the single most important stuff that I care about," says Dag Spicer, curator of the Computer History Museum in Silicon Valley, in his interview with David Pogue. "It's your memory. And when you lose your memory, you lose your personality, you lose who you are. And that's why it's very troublesome that we're taking all of these wonderful pictures and movies, but not thinking about how long they are going to last." Maybe it's something to think about.
Information Preservation
Considering the realities of data rot, what can be done to preserve valuable information? It's really a matter of personal responsibility. There are two primary strategies, and both are important: 1) data migration, and 2) duplication and distribution.
In information technology, migration is the process of moving from the use of one system or medium to another, theoretically one that is new and improved. It is generally agreed that people should migrate their data every five to ten years, which means moving everything you have stored from the old to the new. It may seem forbidding, but if the migration is planned and the data reasonably organized, it should be manageable. System management and migration will be covered in a later article.
The second and perhaps best strategy for preserving information is duplication and distribution. "Making lots of backups is good advice, and on different formats, different places; consider paper as an archival medium. Some paper we have has lasted thousands of years," says Spicer. Sound familiar? It's an old refrain in the genealogy community: duplicate, share, publish. Internet storage is not recommended. As evidenced by the current economy, even big companies can go out of business. This issue of dubious access is discussed in a prior article, Personal Blogs as Historical Documents
Here is the strategy in a nutshell:
- Keep copies of your information on your working system and on the latest portable storage medium.
- Keep a backup copy for yourself and place duplicate copies with others you trust or in safe-keeping, out of your home.
- Check with local archives and libraries to see what materials are accepted and if yours qualifies.
- Keep print copies of your most important information. While some see print as redundant in the computer age, a good paper file is a great backup . . . but it should not be your only source file.
- Finally, consider publishing your work, even in manuscript if not book form. In publishing, copies of your work can end up in various libraries and other diverse places. A good case for publishing was made in the recent article, New England genealogy 101: top 10 reasons to print on paper.
As Spicer observes, "If Moses had gotten the Ten Commandments on a floppy disk, it would never have made it today." And it probably would have challenged the storage capacity of a floppy, anyway.