Questioning Technology: Data for the Ages
Data for the AgesMost computer users, at least the ones who bother to backup their data, have accumulated dozens of magnetic computer disks over the years. These backups may contain everything from personal and business records to letters, graphics, audio and video files from important projects.For those trusting souls who take the promises of the computer industry at face value, there's a certain security in having this archived information easily available for future reference. For a while at least, I was naive enough to believe the promises that my personal files were secure on those cheap, little floppy disks with the "full lifetime warranty." That is before I got a big, nasty surprise.Just as magnetic audio and video recording tape is not forever, those same ephemeral qualities apply to magnetic media for computers. And I don't mean just floppies; this extends to Zip, Jaz, Syquest, tape data cartridges -- any magnetic storage media."The rule of thumb is magnetic media has a half life of five years, no matter which technology you use. That means the magnetic signal that retains the bit on the surface of the media is half as strong as it was when it was recorded. No magnetic media manufacturer claims its product can hold data longer than 10 years," said David Veilleux, marketing manager for Olympus Image Systems.The bottom line, said Veilleux, is "somewhere between six and ten years your data -- in effect -- evaporates. That's because the magnetic field is no longer strong enough to retain the data."So what's a paranoid computer user to do? Essentially there two choices today for serious archiving: record your data on a compact disk or store your files on magneto-optical (MO) media. Though recordable CD technology is getting cheaper and easier to use, the longterm durability and archival life of some low cost CD media is still questionable. However, MO storage -- which has plummeted in price -- is now more desirable than ever for average PC and Mac users.Magneto-optical data storage technology is not new. The federal government has been archiving documents on MO disks for years. The media itself has a shelf life of 30 or more years and is rated for millions of rewritable cycles (about ten times that of typical hard disk drives.) MO media is also highly resistant to data loss caused by dust, shock and temperature extremes. It's virtually immune to magnetic fields.During MO recording, a tiny laser beam heats a small portion (about a micron) of the disk surface to about 500 degrees F. This heat reorganizes the materials in the disk into a crystalline structure that retains the ones and zeros that make up a data file. When the heat dissipates, the data is embedded in the crystals until sufficient heat is reapplied to record over it."It's like heating some wax, putting your fingerprint in the wax and letting the wax solidify again. Until you add the heat again, that fingerprint stays in the wax. It's like a fossilized record," said Veilleux.Once data is recorded onto an MO disk it's very durable. "You can pack an MO cartridge in a box of magnets and ship it around the world and the data is still there," said Veilleux. "Or say you sit on the cartridge and break the housing. With most media that's a disaster. With MO you can put the disk in a new housing. You can even clean the platter with lens cleaning fluid to remove any finger prints."Until recently, the downside of MO was cost. Drives and media were too expensive for use by the average Joe to back up personal files. Now that's changed, thanks to some Japanese computer storage manufacturers like Fujitsu and Olympus. For example, Olympus recently introduced the SYS.230, a low cost MO storage system for personal archiving.The SYS.230 uses 3.5-inch MO cartridges that each hold 230 MB, the equivalent of about 175 floppies worth of data and images. The two-pound portable drive sells for about $300, and cartridges -- rated for a 30 year archival life -- are only $10 each. SYS.230 drives work with any PC (386SX or higher) or Macintosh (Mac OS 6.0.7 or higher).Another important consideration in archiving is compatibility with a wide range of drives from other manufacturers. You don't want to be stuck with some proprietary system that will disappear from the market in a few months. SYS.230 disks, like those from other MO manufacturers, are compatible and can be played back in any of more than two million MO drives currently in use today.Finally, a personal note. This column was born from the ashes of a data disaster. I verified first hand that floppies aren't forever. Some of my old diskettes -- many go back to 1985 -- had already bitten the dust and were no longer readable on any computer. Lesson learned: Whether you use MO or CD for archiving, backup to something NOW if you care about retrieving your old files in the future. Time is not on your side.