Posted on 01/10/2006 6:09:22 PM PST by snarks_when_bored
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Storage expert warns of short life span for burned CDs
News Story by John Blau
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Although opinions vary on how to preserve data on digital storage media, such as optical CDs and DVDs, Kurt Gerecke, a physicist and storage expert at IBM Deutschland GmbH, takes this view: If you want to avoid having to burn new CDs every few years, use magnetic tapes to store all your pictures, videos and songs for a lifetime.
"Unlike pressed original CDs, burned CDs have a relatively short life span of between two to five years, depending on the quality of the CD," Gerecke said in an interview this week. "There are a few things you can do to extend the life of a burned CD, like keeping the disc in a cool, dark space, but not a whole lot more."
The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data "shifting" on the surface and thus becoming unreadable to the laser beam.
"Many of the cheap burnable CDs available at discount stores have a life span of around two years," Gerecke said. "Some of the better-quality discs offer a longer life span, of a maximum of five years."
Distinguishing high-quality burnable CDs from low-quality discs is difficult, he said, because few vendors use life span as a selling point.
Hard-drive disks also have their limitations, according to Gerecke. The problem with hard drives, he said, is not so much the disk itself as it is the disk bearing, which has a positioning function similar to a ball bearing. "If the hard drive uses an inexpensive disk bearing, that bearing will wear out faster than a more expensive one," he said. His recommendation: a hard-drive disk with 7,200 revolutions per minute.
To overcome the preservation limitations of burnable CDs, Gerecke suggests using magnetic tapes, which, he claims, can have a life span of 30 to 100 years, depending on their quality. "Even if magnetic tapes are also subject to degradation, they're still the superior storage media," he said.
But he's quick to point out that no storage medium lasts forever and, consequently, consumers and business alike need to have a plan for migrating to new storage technologies.
"Companies, in particular, need to be constantly looking at new storage technologies and have an archiving strategy that allows them to automatically migrate to new technologies," he said. "Otherwise, they're going to wind up in a dead end. And for those sitting on terabytes of crucial data, that could be a colossal problem."
Good shelf life, sorta low density, though.
Yeah. I have a ton of stuff burned from 98, 99 that still reads fine.
Yeah, true, but the amount of information needed to convey what's really important isn't really all that large (he opined optimistically)...
I just encrypt my data, upload it to P2P networks as "Jessica Simpson Home Porn Video", and let horny geeks mirror my backups for eternity.
I just encrypt my data, upload it to P2P networks as "Jessica Simpson Home Porn Video", and let horny geeks mirror my backups for eternity.
So you're the guy sucking up all my bandwidth...damn you!
"I just encrypt my data, upload it to P2P networks as "Jessica Simpson Home Porn Video", and let horny geeks mirror my backups for eternity."
Whoa. Wait a minute. How does that work? They're thinking they're getting porn, but it's really your run-of-the-mill file storage? That's a great idea.
Hard disk drives keep growing fast enough, and their per-bit cost coming down fast enough, that one should instead keep all data, all versions of all files that anyone might ever care about, on ones disk drive, forever.
Offline storage still has its uses, for disaster recover and for data transportation. But don't use it instead of online storage (don't put your only copy of some useful data on a CD), and don't use it for versioning (keeping track of old versions of stuff.)
I've got stuff dating back 12 years right on my disk in front of me, including from the times I ran DOS, 4DOS, Windows 3.1, OS/2 Warp and some early Linux boots.
Every year or two, I buy a new disk, much bigger than the previous one, and copy it all over, under some folder called "old" or some such.
Then I use removable disks (used to be tape, but now disks are cheaper per bit) for backups, so I always have a few full and recent backups, in different locations.
I've got some old tape, disk, floppy and CD backups, but they are useless. Old stale, unsearchable stuff on media that I probably can't even read anymore. I should throw them out.
Good plan...most people won't (or can't) follow it...
I've got CDs from 6 or 7 years ago that still play, too. But I'm waiting for the dreaded day when they won't...
All kidding aside, I backup online using remote RAID systems networked via VPN and offline using DVDs.
* Top Surface: Silver Printable
* Recording Speed: 4X/8X/16X/24X/48X/52X Certified Write Speed
* Storage Capacity: 80 Minutes / 700MB
* Life: 100 years with proper care / read more than 1,000,000 times
Summary: "No, no, no. They're garbage."
In the LONG LONG TERM, keep refreshing data and resaving it.
In the LONG LONG TERM, keep refreshing data and resaving it.
Yeah, I guess: "Time to make the donuts back-ups..."
Pen, ink, and plain ol' paper turns out to be the best for documents after all. Good for several hundreds of years.
As for photos, old family albums date back to the early 1900's and the photos still look good.
Indeed. The paper ought to be acid-free, though.
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