Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
What are you smoking? Quality burnable optical media has been tested to last nearly 50 years. Granted, these tests are not always 100% accurate. And surely you have DVD movies (replicated) that are more than 3 years old... they have been tested to last nearly 100 years. I recently got some data off of DVD RAMs that I had burned 7 years ago. I have had far more hard drives go bad on me than CDs or DVDs (not including scratched discs, which is a matter of care).
I am not suggesting optical media is as good as tape for archival purposes, but to suggest that optical media is useless for general user backups is rediculous. If data is crucial and you dont have access to tape, make several copies and keep them in different locations. And its one heck of a lot cheaper than tape to boot.
What are you smoking? Quality burnable optical media has been tested to last nearly 50 years. Granted, these tests are not always 100% accurate. And surely you have DVD movies (replicated) that are more than 3 years old... they have been tested to last nearly 100 years. I recently got some data off of DVD RAMs that I had burned 7 years ago. I have had far more hard drives go bad on me than CDs or DVDs (not including scratched discs, which is a matter of care).
I am not suggesting optical media is as good as tape for archival purposes, but to suggest that optical media is useless for general user backups is rediculous. If data is crucial and you dont have access to tape, make several copies and keep them in different locations. And its one heck of a lot cheaper than tape to boot.
Two things:
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
The lifetime of a dvd rental unit is currently at about 10 rentals. While these are clearly not being used for the rare archival processes, I would like to know that the "long term" storage media I am using will last for more than 10 data retrieval sessions.
No study done in three or even ten years can predict with accuracy a lifetime of 100 years...
Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
What medium would you suggest as a cheap, transferable backup method. All magnetic media is basically out as tape drives aren't transferable easily or cheap. Hard drives are unreliable as it is, much less move them around.
I have optical media from years ago that is still fine, used all the time.
I have CD's and DVD's from a heck of lot longer than 3 years ago, both burnable and non-burnable, all of which work fine.
The lifetime of a dvd rental unit is currently at about 10 rentals. While these are clearly not being used for the rare archival processes, I would like to know that the "long term" storage media I am using will last for more than 10 data retrieval sessions.
[/B]
That is ONLY because of misuse.
Before the iPod, I used to lug around burned copies of my CD collection in my car and listened them for ages, over and over and over. And I didnt even keep them in cases, and there was constant humidity change.
Just remember, tape is subject to degredation from humidity, temperature, physical abuse. No one trusts a lone tape backup either... Redundancy is important to any backup scheme, regardless of media.
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
Quote:
It should be noted that results presented in this paper represent continuous exposure to direct light and extreme temperature/humidity levels. The error rates are not representative of discs stored in typical, normal or ideal storage conditions. The results from these tests are to demonstrate, in terms of error rates, the ability of some DVD and CD media to maintain stability given these extreme conditions.
p. 520
Quote:
Other samples using phthalocyanine, samples S6 and S7, perform well in direct light exposure until approximately 600 h, but then a significant increase in BLER and errors in general is seen. These samples have low errors beyond 100 h of aging in extreme temperature/humidity conditions, but again have sharp BLER increase soon afterwards.
p. 521
600h constant exposure to light and 100h exposure to humidity and heat. Heat ranging from 140F to 194F (60-90C) and humidity from 70-90%. Light exposure was 47.5mW/cm2 (I've seen 100-136 mW/cm2 cited for sunlight and 50-60 mW/cm2 for UV from sunlight).
Quote:
It is demonstrated here that CD-R and DVD-R media can be very stable (sample S4 for CD-R and sample D2 for DVD-R). Results suggest that these media types will ensure data is available for several tens of years and therefore may be suitable for archival uses.
Before the iPod, I used to lug around burned copies of my CD collection in my car and listened them for ages, over and over and over. And I didnt even keep them in cases, and there was constant humidity change.
We use the same scheme for our in-car CD player. If a CD-R dies no-harm, no-foul, we just burn another from iTunes. That said, most of the time I use my iPod and iTrip now. CDs are so passé.
But alas, most of the samples failed, and in my experience this is the case with the average cd-r media...
Your experience is that cd-r's fail within a matter of weeks? Where do you keep them? In a greenhouse or your car in the summer? You regularly keep your archival CD-Rs in 140+ degrees temp and 70%+ humidity?
I would call that user error.
Quote:
There is no standard for archival quality and there should be...
Quote:
Unfortunately, it is very difficult for customers to identify these more stable media.
We can pick and choose quotes from this paper all day, but when we get down to it this is the paper's final conclusion...
It may have been difficult prior to the report. Not so much now that at least one manufacturer has built or started marketing their archival quality CD-Rs around the gold coating and phthalocyanine dye combo.
Here are two brands known to use phthalocyanine/gold:
Mitsui (MAM-A) Gold Archival
Delkin Archival Gold
Hard to identify if you are incapable of Googling.
As far as picking and choosing the conclusion on p. 523 clearly states that some brands are very stable and should keep data for several tens of years. It requires some obtuse thinking to come to the direct opposite conclusion based on the findings of this study.
Your experience is that cd-r's fail within a matter of weeks? Where do you keep them? In a greenhouse or your car in the summer? You regularly keep your archival CD-Rs in 140+ degrees temp and 70%+ humidity?
I would call that user error.
70%+ Humidity defines where I grew up. And no, it wasn't that hot, but I have acidentally left a CD-R in direct sun light for a week and it was toast.
Quote:
It may have been difficult prior to the report. Not so much now that at least one manufacturer has built or started marketing their archival quality CD-Rs around the gold coating and phthalocyanine dye combo.
Here are two brands known to use phthalocyanine/gold:
Mitsui (MAM-A) Gold Archival Delkin Archival Gold
Hard to identify if you are incapable of Googling.
And some people who have important data are incapable of googling. You cannot assume that users are brighter than the average tree trunk, it just isn't a safe bet. This is why many many many tech companies make it difficult to delete the root directory of whatever device they make... users are sometimes stupid, sometimes make mistakes, and sometimes just don't have access to this level of information.
Quote:
As far as picking and choosing the conclusion on p. 523 clearly states that some brands are very stable and should keep data for several tens of years. It requires some obtuse thinking to come to the direct opposite conclusion based on the findings of this study.
Vinea
Excuse me? I came to the exact same conclusion that the paper came to: It is difficult for consumers, that is you and I, donchaknow, to identify (apriori) which brands of CD-R and DVD-R are truly archival grade and which will fail in three weeks.
So does the mantra, "The darker the dye the better," still hold true?
Not really. The order appears to be phtalocyanine which is light green/yellow, then Azo which is deep blue followed by Cyanine green-blue/blue.
Gold is better than Gold/Silver which is better than Silver as a reflective layer.
You can probably say that for blue disks but I'd depend on the brand and manufacturer.
If I had some photos I really wanted to archive (on CD-R) I'd buy phthalocyanine+gold disks recommended by some digital photography sites (seems like Kodak Gold Ultima is also a good brand in addition to the two above) and burn a couple archival copies, store them without writing on the CD-Rs in jewel cases and throw one into my little fire safe and one into one of my parent's little fire safe (preferably out of town).
Excuse me? I came to the exact same conclusion that the paper came to: It is difficult for consumers, that is you and I, donchaknow, to identify (apriori) which brands of CD-R and DVD-R are truly archival grade and which will fail in three weeks.
BS:
Quote:
Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
No mention of some brands being better or its hard for the consumer to find good brands. Just 3 year lifetime at the longest. FUD.
Quote:
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
Again, FUD regarding the expected lifetime of disks to be measured in weeks. No statement that some disks were expected by these researchers to last for decades. No indication that the researchers were testing extreme conditions that you typically do not subject your archive disks to (unless your "offsite archival storage" is your car).
The CD-Rs that failed in sunlight were likely of the older/cheaper cyanine variety. The phthalocyanine based CD-Rs that failed after 600 hours would last up to 50 days in direct sunlight.
Yes, some folks can't or wont google. I wouldn't call it "hard" though.
Yes, I can understand human tendencies, including the one where it is difficult to admit you were wrong.
No, I just didn't focus on the exceptions to the overwhelming truth -- Commercial optical storage products have very short lifetimes.
ROFL.
Two last tidbits from NIST and PADI:
Quote:
Among the manufacturers that have done testing, there is consensus that, under recommended storage conditions, CD-R, DVD-R, and DVD+R discs should have a life expectancy of 100 to 200 years or more; CD-RW, DVD-RW, DVD+RW, and DVD RAM discs should have a life expectancy of 25 years or more. Little information is available for CD-ROM and DVD-ROM discs (including audio and video), resulting in an increased level of uncertainty for their life expectancy. Expectations vary from 20 to 100 years for these discs.
Few, if any, life expectancy reports for these discs have been published by independent laboratories. An accelerated aging study at NIST estimated the life expectancy of one type of DVD-R for authoring disc to be 30 years if stored at 25°C (77°F) and 50% relative humidity. This testing for R discs is in the preliminary stages, and much more needs to be done.
Loss of access to digital information stored on optical disks will occur due to both media deterioration and technological obsolescence; of these, technological obsolescence is expected to occur in the shorter time- frame.
Hey, you were only off by an order of magnitude. 3years, 30 years...what's 27 years among friends?
We're more likely not to have a suitable reader than we are to lose the data in our archival CDs.
20-30 years from now? Yeah, I can believe that. How many of us can read 5.25" floppys from 1986?
As applied to Apple and Mac there is the amusing story of how the source code for MacPaint was almost lost but ressurected by cobbling together an old mac to read the floppys which were in Lisa file monitor format...
[split]I am actually getting bored with this discussion... One type of media is expected to last 30 years. ONE!
Let's agree that you can find archival media if you look hard for it, but the average johanna who expects her data to be on that DVD-R she burned yesterday in a year or two isn't necessarily going to be happy when 9/10 times it isn't there...
[B]I am actually getting bored with this discussion... One type of media is expected to last 30 years. ONE!
One they found thus far. Which part of 'testing is in preliminary stages" is confusing you? The part that claims that optical media has at most a 3 year life?
Quote:
Let's agree that you can find archival media if you look hard for it, but the average johanna who expects her data to be on that DVD-R she burned yesterday in a year or two isn't necessarily going to be happy when 9/10 times it isn't there...
Right...90% failure rate after a year. While failures will occur, especially with cheaper media, the circumstance isn't nearly as dire as you keep saying. If johanna sticks her DVD-R in a slip cover that protects it against UV damage. Given most folks don't live in 140+ degree temps that's the most likely failure mode after scratching the thing from mishandling or simply losing it.
Comments
Originally posted by hardeeharhar
Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
What are you smoking? Quality burnable optical media has been tested to last nearly 50 years. Granted, these tests are not always 100% accurate. And surely you have DVD movies (replicated) that are more than 3 years old... they have been tested to last nearly 100 years. I recently got some data off of DVD RAMs that I had burned 7 years ago. I have had far more hard drives go bad on me than CDs or DVDs (not including scratched discs, which is a matter of care).
I am not suggesting optical media is as good as tape for archival purposes, but to suggest that optical media is useless for general user backups is rediculous. If data is crucial and you dont have access to tape, make several copies and keep them in different locations. And its one heck of a lot cheaper than tape to boot.
Originally posted by 4fx
What are you smoking? Quality burnable optical media has been tested to last nearly 50 years. Granted, these tests are not always 100% accurate. And surely you have DVD movies (replicated) that are more than 3 years old... they have been tested to last nearly 100 years. I recently got some data off of DVD RAMs that I had burned 7 years ago. I have had far more hard drives go bad on me than CDs or DVDs (not including scratched discs, which is a matter of care).
I am not suggesting optical media is as good as tape for archival purposes, but to suggest that optical media is useless for general user backups is rediculous. If data is crucial and you dont have access to tape, make several copies and keep them in different locations. And its one heck of a lot cheaper than tape to boot.
Two things:
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
The lifetime of a dvd rental unit is currently at about 10 rentals. While these are clearly not being used for the rare archival processes, I would like to know that the "long term" storage media I am using will last for more than 10 data retrieval sessions.
No study done in three or even ten years can predict with accuracy a lifetime of 100 years...
Originally posted by hardeeharhar
Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
What medium would you suggest as a cheap, transferable backup method. All magnetic media is basically out as tape drives aren't transferable easily or cheap. Hard drives are unreliable as it is, much less move them around.
I have optical media from years ago that is still fine, used all the time.
I have CD's and DVD's from a heck of lot longer than 3 years ago, both burnable and non-burnable, all of which work fine.
Originally posted by hardeeharhar
The lifetime of a dvd rental unit is currently at about 10 rentals. While these are clearly not being used for the rare archival processes, I would like to know that the "long term" storage media I am using will last for more than 10 data retrieval sessions.
[/B]
That is ONLY because of misuse.
Before the iPod, I used to lug around burned copies of my CD collection in my car and listened them for ages, over and over and over. And I didnt even keep them in cases, and there was constant humidity change.
Just remember, tape is subject to degredation from humidity, temperature, physical abuse. No one trusts a lone tape backup either... Redundancy is important to any backup scheme, regardless of media.
Originally posted by hardeeharhar
Two things:
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
It should be noted that results presented in this paper represent continuous exposure to direct light and extreme temperature/humidity levels. The error rates are not representative of discs stored in typical, normal or ideal storage conditions. The results from these tests are to demonstrate, in terms of error rates, the ability of some DVD and CD media to maintain stability given these extreme conditions.
p. 520
Other samples using phthalocyanine, samples S6 and S7, perform well in direct light exposure until approximately 600 h, but then a significant increase in BLER and errors in general is seen. These samples have low errors beyond 100 h of aging in extreme temperature/humidity conditions, but again have sharp BLER increase soon afterwards.
p. 521
600h constant exposure to light and 100h exposure to humidity and heat. Heat ranging from 140F to 194F (60-90C) and humidity from 70-90%. Light exposure was 47.5mW/cm2 (I've seen 100-136 mW/cm2 cited for sunlight and 50-60 mW/cm2 for UV from sunlight).
It is demonstrated here that CD-R and DVD-R media can be very stable (sample S4 for CD-R and sample D2 for DVD-R). Results suggest that these media types will ensure data is available for several tens of years and therefore may be suitable for archival uses.
p. 523
http://www.itl.nist.gov/div895/gipwo...ilityStudy.pdf
Try reading a paper if you're going to actually cite it as a reference.
Vinea
Originally posted by vinea
Try reading a paper if you're going to actually cite it as a reference.
Vinea
Try reading the conclusions of a paper if you are going to attempt to dismiss someone who has read it.
Originally posted by hardeeharhar
Try reading the conclusions of a paper if you are going to attempt to dismiss someone who has read it.
It seems he did read the conclusions. Last quote.
Originally posted by brclark82
It seems he did read the conclusions. Last quote.
But alas, most of the samples failed, and in my experience this is the case with the average cd-r media...
There is no standard for archival quality and there should be...
Edit:
From the Article, sentance following the last quote
Unfortunately, it is very difficult for customers to identify these more stable media.
We can pick and choose quotes from this paper all day, but when we get down to it this is the paper's final conclusion...
Originally posted by 4fx
That is ONLY because of misuse.
Before the iPod, I used to lug around burned copies of my CD collection in my car and listened them for ages, over and over and over. And I didnt even keep them in cases, and there was constant humidity change.
We use the same scheme for our in-car CD player. If a CD-R dies no-harm, no-foul, we just burn another from iTunes. That said, most of the time I use my iPod and iTrip now. CDs are so passé.
Originally posted by hardeeharhar
But alas, most of the samples failed, and in my experience this is the case with the average cd-r media...
Your experience is that cd-r's fail within a matter of weeks? Where do you keep them? In a greenhouse or your car in the summer? You regularly keep your archival CD-Rs in 140+ degrees temp and 70%+ humidity?
I would call that user error.
There is no standard for archival quality and there should be...
Unfortunately, it is very difficult for customers to identify these more stable media.
We can pick and choose quotes from this paper all day, but when we get down to it this is the paper's final conclusion...
It may have been difficult prior to the report. Not so much now that at least one manufacturer has built or started marketing their archival quality CD-Rs around the gold coating and phthalocyanine dye combo.
Here are two brands known to use phthalocyanine/gold:
- Mitsui (MAM-A) Gold Archival
- Delkin Archival Gold
Hard to identify if you are incapable of Googling.As far as picking and choosing the conclusion on p. 523 clearly states that some brands are very stable and should keep data for several tens of years. It requires some obtuse thinking to come to the direct opposite conclusion based on the findings of this study.
Vinea
Originally posted by vinea
Your experience is that cd-r's fail within a matter of weeks? Where do you keep them? In a greenhouse or your car in the summer? You regularly keep your archival CD-Rs in 140+ degrees temp and 70%+ humidity?
I would call that user error.
70%+ Humidity defines where I grew up. And no, it wasn't that hot, but I have acidentally left a CD-R in direct sun light for a week and it was toast.
It may have been difficult prior to the report. Not so much now that at least one manufacturer has built or started marketing their archival quality CD-Rs around the gold coating and phthalocyanine dye combo.
Here are two brands known to use phthalocyanine/gold:
Mitsui (MAM-A) Gold Archival
Delkin Archival Gold
Hard to identify if you are incapable of Googling.
And some people who have important data are incapable of googling. You cannot assume that users are brighter than the average tree trunk, it just isn't a safe bet. This is why many many many tech companies make it difficult to delete the root directory of whatever device they make... users are sometimes stupid, sometimes make mistakes, and sometimes just don't have access to this level of information.
As far as picking and choosing the conclusion on p. 523 clearly states that some brands are very stable and should keep data for several tens of years. It requires some obtuse thinking to come to the direct opposite conclusion based on the findings of this study.
Vinea
Excuse me? I came to the exact same conclusion that the paper came to: It is difficult for consumers, that is you and I, donchaknow, to identify (apriori) which brands of CD-R and DVD-R are truly archival grade and which will fail in three weeks.
How else can I explain this to you?
(Flame deleted - JL)
Originally posted by CosmoNut
So does the mantra, "The darker the dye the better," still hold true?
Not really. The order appears to be phtalocyanine which is light green/yellow, then Azo which is deep blue followed by Cyanine green-blue/blue.
Gold is better than Gold/Silver which is better than Silver as a reflective layer.
You can probably say that for blue disks but I'd depend on the brand and manufacturer.
If I had some photos I really wanted to archive (on CD-R) I'd buy phthalocyanine+gold disks recommended by some digital photography sites (seems like Kodak Gold Ultima is also a good brand in addition to the two above) and burn a couple archival copies, store them without writing on the CD-Rs in jewel cases and throw one into my little fire safe and one into one of my parent's little fire safe (preferably out of town).
Vinea
Originally posted by hardeeharhar
Excuse me? I came to the exact same conclusion that the paper came to: It is difficult for consumers, that is you and I, donchaknow, to identify (apriori) which brands of CD-R and DVD-R are truly archival grade and which will fail in three weeks.
BS:
Optical storage for backup doesn't make sense given that we know that optical media has at the longest a lifetime of 3 years...
No mention of some brands being better or its hard for the consumer to find good brands. Just 3 year lifetime at the longest. FUD.
There was a NIST study from last year which basically indicted almost all of the dyes used in optical storage and indicated that the disks need to be stored in dark dry areas. If either of these suggestions was ignored, the lifetime of the disks was reduced to weeks.
Again, FUD regarding the expected lifetime of disks to be measured in weeks. No statement that some disks were expected by these researchers to last for decades. No indication that the researchers were testing extreme conditions that you typically do not subject your archive disks to (unless your "offsite archival storage" is your car).
The CD-Rs that failed in sunlight were likely of the older/cheaper cyanine variety. The phthalocyanine based CD-Rs that failed after 600 hours would last up to 50 days in direct sunlight.
Yes, some folks can't or wont google. I wouldn't call it "hard" though.
Yes, I can understand human tendencies, including the one where it is difficult to admit you were wrong.
Vinea
Originally posted by hardeeharhar
No, I just didn't focus on the exceptions to the overwhelming truth -- Commercial optical storage products have very short lifetimes.
ROFL.
Two last tidbits from NIST and PADI:
Among the manufacturers that have done testing, there is consensus that, under recommended storage conditions, CD-R, DVD-R, and DVD+R discs should have a life expectancy of 100 to 200 years or more; CD-RW, DVD-RW, DVD+RW, and DVD RAM discs should have a life expectancy of 25 years or more. Little information is available for CD-ROM and DVD-ROM discs (including audio and video), resulting in an increased level of uncertainty for their life expectancy. Expectations vary from 20 to 100 years for these discs.
Few, if any, life expectancy reports for these discs have been published by independent laboratories. An accelerated aging study at NIST estimated the life expectancy of one type of DVD-R for authoring disc to be 30 years if stored at 25°C (77°F) and 50% relative humidity. This testing for R discs is in the preliminary stages, and much more needs to be done.
http://www.itl.nist.gov/div895/caref...dlingGuide.pdf
Loss of access to digital information stored on optical disks will occur due to both media deterioration and technological obsolescence; of these, technological obsolescence is expected to occur in the shorter time- frame.
http://www.nla.gov.au/padi/topics/53.html
Hey, you were only off by an order of magnitude. 3years, 30 years...what's 27 years among friends?
We're more likely not to have a suitable reader than we are to lose the data in our archival CDs.
20-30 years from now? Yeah, I can believe that. How many of us can read 5.25" floppys from 1986?
As applied to Apple and Mac there is the amusing story of how the source code for MacPaint was almost lost but ressurected by cobbling together an old mac to read the floppys which were in Lisa file monitor format...
http://www.pbs.org/cringely/nerdtv/transcripts/001.html
Vinea
Let's agree that you can find archival media if you look hard for it, but the average johanna who expects her data to be on that DVD-R she burned yesterday in a year or two isn't necessarily going to be happy when 9/10 times it isn't there...
Originally posted by hardeeharhar
[B]I am actually getting bored with this discussion... One type of media is expected to last 30 years. ONE!
One they found thus far. Which part of 'testing is in preliminary stages" is confusing you? The part that claims that optical media has at most a 3 year life?
Let's agree that you can find archival media if you look hard for it, but the average johanna who expects her data to be on that DVD-R she burned yesterday in a year or two isn't necessarily going to be happy when 9/10 times it isn't there...
Right...90% failure rate after a year. While failures will occur, especially with cheaper media, the circumstance isn't nearly as dire as you keep saying. If johanna sticks her DVD-R in a slip cover that protects it against UV damage. Given most folks don't live in 140+ degree temps that's the most likely failure mode after scratching the thing from mishandling or simply losing it.
(Flame deleted - JL)
Vinea