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Say Goodbye To Your CD-Rs In Two Years?
Little Hamster writes "According to an article on cdfreaks.com, a test done by the Dutch PC-Active magazine showed that among 30 different CD-R brands tested, a lot of them were already unreadable after twenty months. This is shocking, and makes me wonder how should I backup my data, photo and music collection."
Ahhh, any veteran of the Commodore 1541 floppy drive can tell you what this is: alignment errors. You see, the head is moved using these little step-motors. With use, the motors drift out of alignment, meaning the head moves somewhat less (or more) per "kick" than it's supposed to. As long as it's the same motor, that error occurs on every operation, so there's no net effect. (That is, sure, the data's in the wrong place. But during read-out, the head will seek to the (same) wrong place. So no error.) But move that disk to another machine, whose step-motor has a different alignment, and BAM! read errors.
Fans of the C1541 will remember what happens when that drive found an alignment error: CLACKETY-CLACKETY-CLACKETY-CLACKETY-CLACKETY-CLAC
The Mongrel Dogs Who Teach
I don't consider a backup copy kept within 3 yards of the original copy to be a real backup. Afterall, the point of a backup copy is to survive whatever clamity may befall the original copy.
So please, don't call an HD that is in the same computer, or even the same server rack, your backup. However, a network connected machine on the other side of your building will do just fine.
Do you remember science class where they told you a measurement wasn't correct unless it included a +/- error estimate?
Every CD burner (like every real-world device) has a certain amount of error. The device decides to turn the laser on or off, and there is a delay before the laser turns on or off. This small delay varies with heat and other factors within the device and varies with the component tolerances from device to device.
This error rate is over time, not distance. So, if the CD is rotating slower, it doesn't move as far during the error period. This results in a burn which is closer to perfect, that is it has less error distance than a higher speed burn.
Then there is the completeness of the burn; with a brand new good quality drive it shouldn't matter, but how many of you have a brand new plextor?
And of course there's also the CD media. If you bought the 10 cent bulk discs and expected them to last, shame on you. I record at slow speed to the old dark-blue verbatims whenever I can, and after 7 years I havn't lost data yet.
Moderating "-1, Disagree" is simple censorship. Have the guts to post your opinion.
Why does every porn joke get instantly rated "5, Funny"?
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Yes, but the original poster is also corerct, floppies bought today are total crap compared to years ago. Every floppy disk I've bought in the last few years have all been unreliable at best, but floppies I bought 10 years old still work perfectly.
Here on Slashdot there are many things that divide us, emacs vs. vi, SuSE vs. Debian, the best Dr. Who, all sorts of geeky crap. There is one thing that unites us all- our love of pornography.
-Barry
It is absolutely true. It becomes increasingly difficult to create well-formed pits at higher rotation speeds due to the more difficult timing tolerances. Also, it is easier to get predictable burn results at a lower laser power setting.
Close, but actually it is inducing a color change in an organic dye. This dye is either green (unburned) or clear (burned), and is sandwiched between a reflective and a non-reflective layer.
-- You are in a maze of little, twisty passages, all different... --