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Do BDXL discs have greater longevity than other types of optical media? Back in 2000, our studio switched from archiving our audio recordings on DAT to CD-R. T

Do BDXL discs have greater longevity than other types of optical media? Back in 2000, our studio switched from archiving our audio recordings on DAT to CD-R. Thinking the greatest threats were loss and scratches, they made three copies of every disc and stored them in different locations. Around 2007, all of those CD-R discs started becoming unreadable around the same time. Video recordings were archived to DVD-R starting in 2003 with the same three copy approach. In 2009, after having successfully rescued all our audio recordings on to RAID5 network attached storage, we weren't so lucky with saving our early DVD-R data. I always assumed the reason DVD-R discs lasted less time than CD-R discs before chemical decomposition was because of the greater density, but I never looked into it enough to know for sure. I have to imagine if Amazon is indeed doing this, they have some sort of plan in place to write all data to fresh optical media every five years or so. If so, that would create a very different cost equation.

codezero 12y ago
Just to add some more anecdotal evidence for optical: my group stored satellite data on DVD-Rs, starting in 2003, and in 2012 the earliest discs were still readable. Luckily, we had several forms of back up of the data, so the loss of the DVD-Rs wouldn't have affected us.
batbomb 12y ago
Were you using gold archival quality discs?
- esonderegger 12y ago
  I just went to the drawer to check - It appears as though most of the earliest CD-R discs were HHB gold archival discs. Some of them came from external mastering facilities, so would be on something else. Around 2002, they standardized on Mitsui MAM-A for the archival copies. Interesting enough, those discs have had very few issues. It appears as though the early DVD-R discs were Mitsui MAM-A, with us switching over to Taiyo Yuden in early 2007. Since we have all that stuff on network storage, I haven't gone back to check how the Taiyo Yuden discs have fared over time.
  - hga 12y ago
    When I was last buying media, Taiyo Yuden DVD-R media cost one cent more than their famed CD-R media, for what that's worth. Never had a problem with it, but I've never used it for anything really important (e.g. installation discs were I kept a hard disk copy). This is the first time I can remember ever hearing of HHB gold archival CD-R discs. That's probably not a good sign given how much I was into this field back then, they certainly weren't on the recommended list of anyone I respected. After Kodak stopped making their gold discs, Taiyo Yuden, or Mitsui/MAM-A if you felt like it gave you extra protection. Ah, you did check to make sure that each disc burned could be read back, didn't you?
    - esonderegger 12y ago
      I didn't start working here until 2006, so I don't really know the details of what the process was like back then for testing discs after they had been burned. I assume at least a verification step was involved. Now, when I want to see how bad a disc has gotten, I use PlexTools to do a Q-Check. However, we haven't considered anything on optical media to be a master copy for a while (at least five years). CDs only get burned when someone wants to listen to something in their car.
_red 12y ago
For the same reasons, I've been investigating M-Disc. Requires special writer (but sub-$100), but can be read by any DVD reader. Etches instead of dye, result is claimed 1000 year lifetime. DOD has evidently certified. http://www.mdisc.com/what-is-mdisc/ http://www.mdisc.com/what-is-mdisc/ However, I worry about even finding optical readers in 10 years time.
- esonderegger 12y ago
  Interesting. I hadn't heard of M-Disc. Thanks for the link! The worry of not being able to find a device to read/play back your media is a common one for all storage types, analog and digital. For example, we have hundreds of reels of quarter inch tape from the fifties and sixties down in our library. The tapes themselves are safe (some may need a day in an easy-bake oven), but otherwise they still sound great. We recently had our Studer A-820 refurbished and it's probably in better than new condition, but I worry there won't be any people to do the service, or parts to do the service with if it needs attention in ten years. The more obscure, the medium, the trickier it gets. We have a bunch of early digital recordings stored on Betamax tapes, that need both a working Betamax deck and a PCM encoder-decoder box in order to be read. Fortunately, those have all been transferred now. This is why I'm a believer in thinking of maintaining an archive as being an active rather than static process. It's important to be periodically re-evaluating your digital assets to make sure they can be losslessly transferred to current file formats and modern storage media. It was probably never a good idea to simply "put it on a shelf and forget about it", but thankfully with digital assets, these migrations can be lossless, automated, and tested.
  - barrkel 12y ago
    If you don't have restore drills you don't have backups.
    - esonderegger 12y ago
      Yes, of course. However, backups != preservation. You could have a textbook backup strategy with restore drills and fixity checks making sure that your integrity is 100%. If your audio is stored in Sound Designer II files and your print documents are Word Perfect files, you are probably not being a good steward of your data.
hga 12y ago
According to something of an expert in the field (she holds a fist full of patents, several of which are used in every hard drive you own), DVD-R's pushed CD-R technology too far. Even using Misui/MAM-A Gold media is no great guarantee. CD-Rs ... who made the discs, and how did you store them? Or did you buy a huge batch at once? I've had great success for over a decade with Taiyo Yuden CD-Rs, over 3,000 recorded and not a single failure to read that wasn't due to a bad read drive, easily solved by using another. Although those retrieval results aren't yet statistically significant.
- esonderegger 12y ago
  I didn't start working here until 2006, so I don't really know how they were purchased, but they didn't standardize on Mitsui MAM-A until 2002 or so. Before then, there was an assortment of gold media from different brands. The masters have been stored in standard jewel cases in drawers in our office. I've also had great luck with the Taiyo Yuden CD-Rs. We go through about a thousand discs a year for people who prefer to have a CD copy of their music to being able to download a file, and I can't remember the last time I had a failure. However, now that our master copies are 24-bit wav files on network storage, I haven't been as concerned with how those discs have been aging. I suppose we probably have enough samples for an interesting study on the longevity of optical media, but unfortunately I just don't see us having the time to devote to something like that.
KaiserPro 12y ago
This is why I was suprised that FB were so keen on BDXL. There is no long term data on stability. they are incredibly fragile and prone to delamination.
sp332 12y ago
DVD-RAM discs were much more reliable than DVD-RW, and the chemistry has only gotten better since then. And write-once BD-Rs actually use melting metal instead of dye, so they are extremely stable with some companies advertising 50 year shelf lives.
snowwrestler 12y ago
-R discs store data via a dye layer that changes color when hit by the laser. The dyes are not known to hold color durably. I don't have the links now but I've read studies that estimated CD-Rs could fail within 7-10 years. -RW discs supposedly last a lot longer because the RW tech uses a phase change metal instead of dye, and the phase changes are more durable.

codezero 12y ago

Just to add some more anecdotal evidence for optical: my group stored satellite data on DVD-Rs, starting in 2003, and in 2012 the earliest discs were still readable. Luckily, we had several forms of back up of the data, so the loss of the DVD-Rs wouldn't have affected us.

batbomb 12y ago

Were you using gold archival quality discs?

esonderegger 12y ago
I just went to the drawer to check - It appears as though most of the earliest CD-R discs were HHB gold archival discs. Some of them came from external mastering facilities, so would be on something else. Around 2002, they standardized on Mitsui MAM-A for the archival copies. Interesting enough, those discs have had very few issues. It appears as though the early DVD-R discs were Mitsui MAM-A, with us switching over to Taiyo Yuden in early 2007. Since we have all that stuff on network storage, I haven't gone back to check how the Taiyo Yuden discs have fared over time.
- hga 12y ago
  When I was last buying media, Taiyo Yuden DVD-R media cost one cent more than their famed CD-R media, for what that's worth. Never had a problem with it, but I've never used it for anything really important (e.g. installation discs were I kept a hard disk copy). This is the first time I can remember ever hearing of HHB gold archival CD-R discs. That's probably not a good sign given how much I was into this field back then, they certainly weren't on the recommended list of anyone I respected. After Kodak stopped making their gold discs, Taiyo Yuden, or Mitsui/MAM-A if you felt like it gave you extra protection. Ah, you did check to make sure that each disc burned could be read back, didn't you?
  - esonderegger 12y ago
    I didn't start working here until 2006, so I don't really know the details of what the process was like back then for testing discs after they had been burned. I assume at least a verification step was involved. Now, when I want to see how bad a disc has gotten, I use PlexTools to do a Q-Check. However, we haven't considered anything on optical media to be a master copy for a while (at least five years). CDs only get burned when someone wants to listen to something in their car.

_red 12y ago

For the same reasons, I've been investigating M-Disc. Requires special writer (but sub-$100), but can be read by any DVD reader. Etches instead of dye, result is claimed 1000 year lifetime. DOD has evidently certified. http://www.mdisc.com/what-is-mdisc/ http://www.mdisc.com/what-is-mdisc/ However, I worry about even finding optical readers in 10 years time.

esonderegger 12y ago
Interesting. I hadn't heard of M-Disc. Thanks for the link! The worry of not being able to find a device to read/play back your media is a common one for all storage types, analog and digital. For example, we have hundreds of reels of quarter inch tape from the fifties and sixties down in our library. The tapes themselves are safe (some may need a day in an easy-bake oven), but otherwise they still sound great. We recently had our Studer A-820 refurbished and it's probably in better than new condition, but I worry there won't be any people to do the service, or parts to do the service with if it needs attention in ten years. The more obscure, the medium, the trickier it gets. We have a bunch of early digital recordings stored on Betamax tapes, that need both a working Betamax deck and a PCM encoder-decoder box in order to be read. Fortunately, those have all been transferred now. This is why I'm a believer in thinking of maintaining an archive as being an active rather than static process. It's important to be periodically re-evaluating your digital assets to make sure they can be losslessly transferred to current file formats and modern storage media. It was probably never a good idea to simply "put it on a shelf and forget about it", but thankfully with digital assets, these migrations can be lossless, automated, and tested.
- barrkel 12y ago
  If you don't have restore drills you don't have backups.
  - esonderegger 12y ago
    Yes, of course. However, backups != preservation. You could have a textbook backup strategy with restore drills and fixity checks making sure that your integrity is 100%. If your audio is stored in Sound Designer II files and your print documents are Word Perfect files, you are probably not being a good steward of your data.

hga 12y ago

According to something of an expert in the field (she holds a fist full of patents, several of which are used in every hard drive you own), DVD-R's pushed CD-R technology too far. Even using Misui/MAM-A Gold media is no great guarantee. CD-Rs ... who made the discs, and how did you store them? Or did you buy a huge batch at once? I've had great success for over a decade with Taiyo Yuden CD-Rs, over 3,000 recorded and not a single failure to read that wasn't due to a bad read drive, easily solved by using another. Although those retrieval results aren't yet statistically significant.

esonderegger 12y ago
I didn't start working here until 2006, so I don't really know how they were purchased, but they didn't standardize on Mitsui MAM-A until 2002 or so. Before then, there was an assortment of gold media from different brands. The masters have been stored in standard jewel cases in drawers in our office. I've also had great luck with the Taiyo Yuden CD-Rs. We go through about a thousand discs a year for people who prefer to have a CD copy of their music to being able to download a file, and I can't remember the last time I had a failure. However, now that our master copies are 24-bit wav files on network storage, I haven't been as concerned with how those discs have been aging. I suppose we probably have enough samples for an interesting study on the longevity of optical media, but unfortunately I just don't see us having the time to devote to something like that.

KaiserPro 12y ago

This is why I was suprised that FB were so keen on BDXL. There is no long term data on stability. they are incredibly fragile and prone to delamination.

sp332 12y ago

DVD-RAM discs were much more reliable than DVD-RW, and the chemistry has only gotten better since then. And write-once BD-Rs actually use melting metal instead of dye, so they are extremely stable with some companies advertising 50 year shelf lives.

snowwrestler 12y ago

-R discs store data via a dye layer that changes color when hit by the laser. The dyes are not known to hold color durably. I don't have the links now but I've read studies that estimated CD-Rs could fail within 7-10 years. -RW discs supposedly last a lot longer because the RW tech uses a phase change metal instead of dye, and the phase changes are more durable.