DVD / CD longevity

[Gambit37]

What's your experience of the longevity of your CD or DVD backups?

I recently tried to get some stuff off a DVD I made just 2.5 years ago and it's unreadable.

I know that there is a huge disparity between good and bad media and the type of dye used also affects longevity. I'm not sure the manufacturer ID of the failed disc, will need to check, but if you know about these things, you'll known that certain disc IDs (RICOHJPNR03, YUDEN000T03) represent better quality and longevity than other IDs (OPTO, CMC).

I would have hoped that my discs would have lasted longer than 2.5 years. Some analysts say CDs and DVDs should last several decades under optimum conditions, while others say that you should check (and duplicate) your backups every six months!

There is some interesting discussion here:

http://club.cdfreaks.com/f33/dvd-r-medi ... ge-183684/


What are your experiences? Do you use a particular disc that always works? Have you checked old backups and found them unreadable?

More to the point, can you recommend good recovery software that might be able to read my "unreadable" disc?

[ChristopheF]

The very first CDs that I burnt myself were of Kodak brand, in 1993 or 1994. Back at the time, that was under windows 3.1 and you had to stop moving the mouse while burning or it would fail! Burning a complete CD at 1x took 74 minutes !

It was very slow, touchy and expensive, but today I can still read these CDs without any problem.
However, many of the CDs and DVDs that I burnt far more recently have become unreadable after a few years, even months in some cases. I tried brands like Sony, Traxdata, no names, Verbatim,...

For me, choosing the right media is an impossible mission. You can't know if you made the good choice until you try to read your data years later to discover it's not working anymore.
So I have stopped burning data to DVDs and now I backup my data on hard disks!

[Gambit37]

Yeah, I think extra hard-drives is the better way to go, though annoyingly I have just ordered a load more blank DVDs...

I remember the first CD-ROM burner I used back in '93 cost several thousand pounds! What are they now, like £9 or something?

[cowsmanaut]

I have discs I burned from 99 and 01 that I burned which seem to be in good order still.. maxell CDs.. don't know about any 2 year old DVD's need to check. but I've gone back to a lot of old CDs and found them all to be fine..

[Bit]

Have no problems with CDs so far - haven't DVD burner yet.
Think most important is darkness and no high temperatures.

[Paul Stevens]

DVDs heh? I have approximately
4000 'coasters' in my collection. Let
me tell you that I have suffered a
great deal of pain.

1) I made several thousand DVDs. I
put labels on them. Very nice. Months
later the labels dried out. The disks
warped because the labels shrank.
The folks who sell the labels don't tell
you this will happen. Some disks ok
because I did not write all the way to the
edge and so the read head could follow.
I copied almost all of them by removing
labels, pressing them, and doing whatever
it took. Almost all were RIDATA.
Easy to see the warp when viewed at a
very small angle. The copies were made
on printable disks so I print the labels
directly on the disk.

2) Ran out of room keeping the disks in
thin-line cases. Bought about 30 wallets.
Very nice and compact. Room for me in
my home again. After a few months every
disk has been very permanently warped by
the wallet being closed and pressing on the
edges of the disks. The disks are thicker
in the middle because of the 'stacking' rings
and therefore you can press down the edges
of a stack of them. 75 percent unreadable.
The ones in the center of the wallet OK.
Managed to copy most of them by getting
a different drive that, I guess, could follow
the warp---slowly. The folks who sell those
wallets don't mention that this will happen.
Mostly RIDATA. Easy to see the warp at
a very small angle but you have to turn it
to the right position, look at it with both
eyes, the left eye across a diameter and
the right eye across near an edge. The
resulting reflections won't line up and you
see two images.

3) Now I keep my latest copies in cake boxes.
Twenty-five to a box and four boxes to a pile.
Mostly PRODISC. Years without failure. They
all look nice and flat. They are kept on a high
shelf where the sun don't shine. Not so
convenient to access but I only get a couple
per day.

4) The thousands of originals and first copies
are kept in cake boxes, 100 to the box, in the
basement as backups in case something else
goes wrong. So far I have had to access
them only in cases where I managed damage
the current copy by accident or anger.

Therefore, I report that in my experience,
the longevity is a physical problem, not a
problem with the dye. Also, I think CDs are
much less sensitive. I have CDs that are
obviously warped but they still work OK. I
suppose because the bits are bigger and the
read head floats farther from the surface or
whatever.

[Tom Hatfield]

Burn your discs at a slower rate. Faster burning reduces the impression and leaves the discs vulnerable to natural wear. That's why discs made ten years ago with slower burners last longer than the ones you burn today. Longevity has very little to do with media quality. Personally, I never go faster than 4x, with either CD's or DVD's.

[ian_scho]

Wow Tom. That's an interesting fact. Thanks man.

[Gambit37]

I can only burn DVDs at 4x anyway -- they still deteriorate, so what does that prove?

[Tom Hatfield]

That could be a media problem. You might be skirting the "very little" side of the equation.