Hi,

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i don't
exist" in order to get "Finder" to read through every file on the CD rom as a
way to check for corrupt data. Note: "Finder" has reported read errors on
some of my floppy disks. So far, no read errors were reported. However, I
started burning CD roms about 4 years ago.

Is the integrity of commercial CD roms better than those I "burn" at home?
How long can we expect to keep our CD roms, assuming they are stored in a good
environment, before we begin to encounter corrupt data?

Thanks in advance, Brad

Before you type your password, credit card number, etc.,
be sure there is no active key logger (spyware) in your PC.

"Brad" wrote in message
...
Hi,

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i
don't
exist" in order to get "Finder" to read through every file on the CD rom
as a
way to check for corrupt data. Note: "Finder" has reported read errors on
some of my floppy disks. So far, no read errors were reported. However,
I
started burning CD roms about 4 years ago.

Is the integrity of commercial CD roms better than those I "burn" at
home?
How long can we expect to keep our CD roms, assuming they are stored in a
good
environment, before we begin to encounter corrupt data?

The simple answer to that seems to be 'no-one knows for certain'. I've read
10 and 25 years, but I take such claims with a pinch of salt. Just look at
laser discs, some of them were inherently faulty and developed 'sparkles' as
they deteriorated over the years. Unfortunately, it seems no data storage
medium is even close to perfect.

Dave

"Brad" wrote in message
...
Hi,

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i
don't
exist" in order to get "Finder" to read through every file on the CD rom
as a
way to check for corrupt data. Note: "Finder" has reported read errors on
some of my floppy disks. So far, no read errors were reported. However,
I
started burning CD roms about 4 years ago.

Is the integrity of commercial CD roms better than those I "burn" at
home?

Apples to oranges. Factory discs are not burned, they are pressed (i.e.,
molded) in the desired pattern. Writeable discs use dyes which are fixed by
the laser light to store the pattern. Hence, pressed CD's don't generally
degrade from subsequent exposure to the wrong kinds of light as do burned
discs. Extending the topic a little to DVD's, there is an unfortunate
phenomenon known as "rotting" which occurs even on factory discs. This
happens when defective bonding leads to layer separation.

How long can we expect to keep our CD roms, assuming they are stored in a
good
environment, before we begin to encounter corrupt data?


It varies. Assuming identical storage solutions, the main difference is in
brands used. But even that's hotly debated. You'll find users of the
cheapest crap on the planet proudly proclaiming their discs have lasted 5+
years, while others wouldn't touch them with a ten foot pole. Brand loyalty
comes into play as well. If you loved your old verbatim floppies, you might
want to stick with verbatim CD's, etc. I personally buy name brand
cakeboxes that offer the best value at that time. Usually, they end up
being TDK and Maxell, both of which have produced very good magnetic media
over the years and I have no prob trusting either company's CD's.

As a general rule of thumb with optical media, you should back up the most
precious data at least once a year. That includes DVD's. Data you can
afford to lose might get backed up once every few years. There's enough
evidence to clearly indicate the hype when writeable optical discs first
came out was utterly bogus. Your recording will last a hundred years!!??
Pretty funny.

"Dave D" writes:

"Brad" wrote in message
...
Hi,

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i
don't
exist" in order to get "Finder" to read through every file on the CD rom
as a
way to check for corrupt data. Note: "Finder" has reported read errors on
some of my floppy disks. So far, no read errors were reported. However,
I
started burning CD roms about 4 years ago.

Is the integrity of commercial CD roms better than those I "burn" at
home?
How long can we expect to keep our CD roms, assuming they are stored in a
good
environment, before we begin to encounter corrupt data?

The simple answer to that seems to be 'no-one knows for certain'. I've read
10 and 25 years, but I take such claims with a pinch of salt. Just look at
laser discs, some of them were inherently faulty and developed 'sparkles' as
they deteriorated over the years. Unfortunately, it seems no data storage
medium is even close to perfect.

This is certainly true. I think the cool storage is fine but it should
also be dry. Dark probably doesn't matter that much as long as there
isn't much UV.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

Sam Goldwasser wrote:
"Dave D" writes:

"Brad" wrote in message
...
Hi,

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i
don't
exist" in order to get "Finder" to read through every file on the CD rom
as a
way to check for corrupt data. Note: "Finder" has reported read errors on
some of my floppy disks. So far, no read errors were reported. However,
I
started burning CD roms about 4 years ago.

Is the integrity of commercial CD roms better than those I "burn" at
home?
How long can we expect to keep our CD roms, assuming they are stored in a
good
environment, before we begin to encounter corrupt data?
The simple answer to that seems to be 'no-one knows for certain'. I've read
10 and 25 years, but I take such claims with a pinch of salt. Just look at
laser discs, some of them were inherently faulty and developed 'sparkles' as
they deteriorated over the years. Unfortunately, it seems no data storage
medium is even close to perfect.

This is certainly true. I think the cool storage is fine but it should
also be dry. Dark probably doesn't matter that much as long as there
isn't much UV.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.


One thing i learned recently about optical disks disturbed me. I had
always taken the most care to protect the data side of the disk. I
found out that the most fragile side is actually the one with the label.
It's the one closest to the actual media. A scratch there--one which
might not even glitch a reader if it were on the other side--can expose
the metallic layer to corrosion.

jak

jakdedert writes:

One thing i learned recently about optical disks disturbed me. I had
always taken the most care to protect the data side of the disk. I
found out that the most fragile side is actually the one with the
label. It's the one closest to the actual media. A scratch there--one
which might not even glitch a reader if it were on the other side--can
expose the metallic layer to corrosion.

Yeah, and a piece of sticky tape may pull it off entirely on CD-R/RWs!

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

On 2006-03-18, Sam Goldwasser wrote:
jakdedert writes:

One thing i learned recently about optical disks disturbed me. I had
always taken the most care to protect the data side of the disk. I
found out that the most fragile side is actually the one with the
label. It's the one closest to the actual media. A scratch there--one
which might not even glitch a reader if it were on the other side--can
expose the metallic layer to corrosion.

Yeah, and a piece of sticky tape may pull it off entirely on CD-R/RWs!

That's why I've never used CD-labels. I used to label my CDs directly
with permanent OHP pens, but now I use specialized CD pens. (I think
the price is about the same these days.)

On 17 Mar 2006 22:31:21 -0500, Sam Goldwasser wrote:

jakdedert writes:

One thing i learned recently about optical disks disturbed me. I had
always taken the most care to protect the data side of the disk. I
found out that the most fragile side is actually the one with the
label. It's the one closest to the actual media. A scratch there--one
which might not even glitch a reader if it were on the other side--can
expose the metallic layer to corrosion.

Yeah, and a piece of sticky tape may pull it off entirely on CD-R/RWs!


Hmmm, that sounds like the voice of experience!
--

Australia isn't "down under", it's "off to one side"!


www.cobracat.com (home of the Australian Cobra Catamaran)
http://groups.yahoo.com/group/cobra-cat/

Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

Bill
=============================

Adam Funk wrote:

That's why I've never used CD-labels. I used to label my CDs directly
with permanent OHP pens, but now I use specialized CD pens. (I think
the price is about the same these days.)

Sam Goldwasser wrote:

This is certainly true. I think the cool storage is fine but it should
also be dry.

Sam -

Some of us don't have the advantage of a dry climate. Here in Arizona
things are usually quite dry, for example. But I have half of my DVDs
stored on the coast in Maine, where it is quite humid at least 9 months
of the year. I assume it would be helpful to put my DVDs in some sort
of waterproof box - even a big Tupperware box - and toss in a couple of
the "Do Not Eat" silica gel packets that come in bags of rice crackers
and other crispy foods?

Bill

"Bill Jeffrey" wrote in message
news:2CWSf.9131$z82.8920@fed1read07...
Adam -

I would think that a CD label would be a GOOD thing, as long as you don't
pull it off (and why would you?). It would be a barrier against the
inadvertent scratches that happen during handling. Yes? No? It would
also tend to keep ambient light out of the disk - or at least the side
that is normally stored upward, facing the light.


The adhesive on labels contains solvents which may compromise the CD's
coating over time, or even break it down altogether. I personally would
never attach anything sticky to my CDs or DVDs, least of all my most
precious and irreplaceable ones.

Dave

On 2006-03-18, Bill Jeffrey wrote:
Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

I've been under the impression that the adhesives damage the coating.
(I could be wrong.)

Adam Funk writes:

On 2006-03-18, Bill Jeffrey wrote:
Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

I've been under the impression that the adhesives damage the coating.
(I could be wrong.)

It's possible. Some solvents will make the coating literally peel off on
its own.

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.

"Adam Funk" wrote in message
...
On 2006-03-18, Bill Jeffrey wrote:
Adam -

I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?). It would be a barrier against
the inadvertent scratches that happen during handling. Yes? No? It
would also tend to keep ambient light out of the disk - or at least the
side that is normally stored upward, facing the light.

I've been under the impression that the adhesives damage the coating.
(I could be wrong.)

Labels aren't permanent and can cause a variety of problems; among the ones
I've seen are causing jamming in slot-loading machines, and clamping
problems in regular tray or carousel models. On a regular machine, if any
adhesive migrates a bit, the disc can stick to the clamper and also cause
jamming problems.


Mark Z.

Dave D wrote:

"Bill Jeffrey" wrote in message
news:2CWSf.9131$z82.8920@fed1read07...

Adam -

I would think that a CD label would be a GOOD thing, as long as you don't
pull it off (and why would you?). It would be a barrier against the
inadvertent scratches that happen during handling. Yes? No? It would
also tend to keep ambient light out of the disk - or at least the side
that is normally stored upward, facing the light.



The adhesive on labels contains solvents which may compromise the CD's
coating over time, or even break it down altogether. I personally would
never attach anything sticky to my CDs or DVDs, least of all my most
precious and irreplaceable ones.

Dave

Thanks, Dave. Didn't know that.

Bill

On 2006-03-18, Dave D wrote:

The adhesive on labels contains solvents which may compromise the CD's
coating over time, or even break it down altogether. I personally would
never attach anything sticky to my CDs or DVDs, least of all my most
precious and irreplaceable ones.

Thanks. I'll keep using the CD pens.

On Fri, 17 Mar 2006 20:58:18 GMT, (Brad) put
finger to keyboard and composed:

From time to time, I come across an article about CD roms, etc.
What I have learned so far, CD-R (I use) is better than CD-RW for long
term storage of important data. Also, how they are stored can have
a bearing on their "life".

I keep CD roms in a dark cool location. To test the integrity of my
"burned" CD roms, I use "Finder" (search engine) I downloaded from
www.simtel.net. I "search" for a non-existant text pattern such as "i don't
exist" in order to get "Finder" to read through every file on the CD rom as a
way to check for corrupt data.

Is that for the Windows platform? If so, doesn't Windows' built-in
"Find Files and Folders" function do the same thing?

Otherwise, try this from a DOS prompt:

echo f | xcopy d:\ nul /c /h /s %temp%.\readtest.txt

This reads every file on the CD-ROM (drive D and copies it to the
NUL device, ie into the bit bucket. The results of each read are
recorded in readtest.txt.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

In article 2CWSf.9131$z82.8920@fed1read07,
Bill Jeffrey wrote:
I would think that a CD label would be a GOOD thing, as long as you
don't pull it off (and why would you?).

*You* may not pull it off, however, your 68x SoopaDVDCombo drive may well
do that, in passing. The resulting mess will not be pretty. I've had
labels start to peel at the edges. The discs were clean, the labels not
"handled" at the edge. The discs were well stored.

Fortunately, the disks had a rhino hide coating on them that allowed the
label to be soaked off. I've stopped using labels since. I just don't
trust them to stick properly!

To the poster talking of "Finder", running a program to read all the
data is one way of knowing that it's TOO LATE for some of your data.

However, you can get an early warning of impending failure by using a
PROPER utility like Nero CD-Speed. This will run over the disk and show
you a count of C1 and C2 errors. On most disks you get a handful of C1
errors (low level) over the disk. And maybe a C2 error or two. These aren't
a problem. If you scan a disk and get hundreds of C1 errors, or handfuls
of C2 errors, then your disk is on the way out. Copy it ASAP. You get a
feel for what is "normal" after running CDROMS, CD-Rs etc. through
the drive. A really bad "C-GRADE NONAME CDR" will look like the side
of a mountain, as the C1 error count starts off and ramps into the
THOUSANDS.

This scan is done BEFORE you get to the state of data corruption where
the OS is sitting there saying "File error". Error correction is a wonderful
thing, but could be hiding the fact that your data is g=tting v ry fl ky
ind%!d.

Mike.
--
--------------------------------------+------------------------------------
Mike Brown: mjb[at]pootle.demon.co.uk | http://www.pootle.demon.co.uk/

In article ,
Stan Blazejewski wrote:

Yeah, and a piece of sticky tape may pull it off entirely on CD-R/RWs!
Hmmm, that sounds like the voice of experience!

I've seen a set of CDs "helpfully" labelled with 3-M PostIts[tm] to
aid identification: "This CD Works" "This didn't boot" etc.

After removal of the PostIt, most of them could be labelled with "This
Is Now Scrap" "Another Coaster" "Look At The Cool Blue Window In This CD"
as it pulled the metallisation right off.

This is not normal for CD-Rs, however, somebody forgot to lacquer coat the
shiny side of the disks, and that would be why they were so cheap. Penny
pinching purchasing department strikes again.

--
--------------------------------------+------------------------------------
Mike Brown: mjb[at]pootle.demon.co.uk | http://www.pootle.demon.co.uk/

Apples to oranges. Factory discs are not burned, they are pressed (i.e.,
molded) in the desired pattern. Writeable discs use dyes which are fixed by
the laser light to store the pattern. Hence, pressed CD's don't generally
degrade from subsequent exposure to the wrong kinds of light as do burned
discs. Extending the topic a little to DVD's, there is an unfortunate
phenomenon known as "rotting" which occurs even on factory discs. This
happens when defective bonding leads to layer separation.
Some of the separation can be attributed to exposure to temperature
variations. As each material (metal, plastic a, plastic b-coating,
etc.) expands and contracts at differing rates, separation at mostly the
edges where stresses are greatest begins to show up as a "feathering
discolorization"

Don't store cds or dvds near heat or near cold sources as this will
reduce life of the data. Constant, cool temperatures are the rule.

Cheers, Hank