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Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

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Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#111
Once made a quick $5k, because a former client had started using CD-RW for their "enterprise" backups, 10-years later they had unreadable data and contacted me to see if I still had some source-code.

Checked my stack of hard-drives, and... Yes... yes, I did have a working copy.

That cemented it in my personal world - NAS with also HD's is the way to go.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#112
post #9

I used to be concerned about optical media longevity. I bought Taiyo-Yuden discs. I checked their integrity. I stored them carefully. But the format became obsolete (for me) long before the media degraded. Recordable discs are just too small for the backup use case I had. Optical drives are still available of course, but they are now rarely standard with a new PC or laptop, and soon will become specialist components,…

> Optical drives are still available of course, but they are now rarely standard with a new PC or laptop, and soon will become specialist components, and then it won’t be long before the drives become a greater limit to longevity than the media. IMO, the #1 use case for optical drives is probably playing music in the car. For anything old enough that it doesn't have an aux port, it's the best solution. * Tape adapter…

> IMO, the #1 use case for optical drives is probably playing music in the car. For anything old enough that it doesn't have an aux port, it's the best solution.

Not even that old. A friend of mine bought a BMW MY2020 and it still has a CD-player (it was an extra, but it was at least still available in 2020).

I wouldn't be surprised if you could still order new car, today, with a CD player.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#113
post #66

Totally anecdotal but just a month ago I opened a box from my last moving (ended 4 years ago...) and I found a CD-RW labeled "Backup 2001", which survived 5-6 relocations, even an international one. Well, I put it into an USB DVD player I have aaaand, it starts spinning and spinning and spinning, and nothing shows up in Nautilus. Looking at dmesg I see a few I/O errors on the device. Then, I try ddrescue [1], start e…

Even with ddrescue you might lose a few bits. You will only find out when accessing those specific files and bits. For my photo history I prefer to keep PAR files next to it. On a running mechanical disc I haven't seen issues when running the repair. I do expect to see some errors in the future and as long as it stays under a certain percentage, things will be fixable. I started doing this long time in the past, when…

Could you explain the PAR file and why that would help?

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#114
post #66

Totally anecdotal but just a month ago I opened a box from my last moving (ended 4 years ago...) and I found a CD-RW labeled "Backup 2001", which survived 5-6 relocations, even an international one. Well, I put it into an USB DVD player I have aaaand, it starts spinning and spinning and spinning, and nothing shows up in Nautilus. Looking at dmesg I see a few I/O errors on the device. Then, I try ddrescue [1], start e…

Even with ddrescue you might lose a few bits. You will only find out when accessing those specific files and bits. For my photo history I prefer to keep PAR files next to it. On a running mechanical disc I haven't seen issues when running the repair. I do expect to see some errors in the future and as long as it stays under a certain percentage, things will be fixable. I started doing this long time in the past, when…

If you pay attention to the ddrescue output it is pretty obvious when you are missing a few bytes here and there.

I have long since moved away from optical media, really for anything, but especially archival. Long term storage to me looks like an array of magnetic disks held together with ZFS.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#115
post #86

Totally anecdotal but just a month ago I opened a box from my last moving (ended 4 years ago...) and I found a CD-RW labeled "Backup 2001", which survived 5-6 relocations, even an international one. Well, I put it into an USB DVD player I have aaaand, it starts spinning and spinning and spinning, and nothing shows up in Nautilus. Looking at dmesg I see a few I/O errors on the device. Then, I try ddrescue [1], start e…

>Outlook Express format http://fileformats.archiveteam.org/wiki/Outlook_Express_Data...

Nice link, thanks! With my searches I wasn't able to find it but this [1] looks promising. Let see how bit rot affects a 8 years old Linux release...

[1] https://sourceforge.net/projects/ol2mbox/

EDIT: mmh looks like it's now `libpst` and it's actually in the Debian/Ubuntu repos...

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#116
post #66

Earlier quoted context omitted.

Even with ddrescue you might lose a few bits. You will only find out when accessing those specific files and bits. For my photo history I prefer to keep PAR files next to it. On a running mechanical disc I haven't seen issues when running the repair. I do expect to see some errors in the future and as long as it stays under a certain percentage, things will be fixable. I started doing this long time in the past, when…

Could you explain the PAR file and why that would help?

PAR files are a form of Forward Error Correction (FEC) (implemented with Reed Solomon). They can be used to repair some percentage of damaged blocks in a file or set of files. The percentage is determined ahead of time when you generate the FEC (PAR files) and imposes the same amount of storage overhead (i.e., 15% redundancy costs 15% additional disk space with Reed-Solomon).

https://en.wikipedia.org/wiki/Error_correction_code#Forward_...

https://en.wikipedia.org/wiki/Reed%E2%80%93Solomon_error_cor...

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#117

Earlier quoted context omitted.

A desktop CNC engraver can be had for $500. Stones are cheap. Archaeologists have read engraved stones after thousands of years of neglect!

And how many did they fail to read?

The ones where the cavemen forgot to engrave checksum data.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#118

Earlier quoted context omitted.

A desktop CNC engraver can be had for $500. Stones are cheap. Archaeologists have read engraved stones after thousands of years of neglect!

And how many did they fail to read?

Of the ones that were stored appropriately, virtually all are still readable.

Whether the format it was written in is still comprehensible could be a more pertinent question.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#119
post #23

Earlier quoted context omitted.

I was a fan of the matte white top printable taiyo udens. Back in my sharing early days, I probably had like 1000+ dvds of anime, movies, hk film, games etc easily. I had so much media that I didn't have time to watch it all, let alone watch it again in the future (there are some gems that I actually went out and purchased retail copies). Plus alot of the shit would get released at higher quality making my archive ob…

In my case it was early MMA fights, I was obssessed with martial arts in general, and up to 2007 I literally had a 500+ collection of burned CDs and DVDs, with every single fight from every major promotion in the world, catalogued by date, fighter's involved, styles, results etc. Until someday I realized that I probably would never rewatch any of those fights, I would simply watch the new ones that are happening ever…

I recently left my home for an apartment and came to the same conclusion about accumulated stuff. Watches, guns, calculators, shirts, shoes were all bad but worst of all trying to cram 1000 lbs of books into a two bedroom apartment is ridiculous. I am working on minimizing but it is hard to let go of these objects that I love. Thankfully I have long since moved my data hoard off to cloud storage so at least that only costs money.

Re: Longevity of Recordable CDs, DVDs and Blu-Rays (2020)

#120

Earlier quoted context omitted.

> Optical drives are still available of course, but they are now rarely standard with a new PC or laptop, and soon will become specialist components, and then it won’t be long before the drives become a greater limit to longevity than the media. IMO, the #1 use case for optical drives is probably playing music in the car. For anything old enough that it doesn't have an aux port, it's the best solution. * Tape adapter…

> IMO, the #1 use case for optical drives is probably playing music in the car. For anything old enough that it doesn't have an aux port, it's the best solution. Not even that old. A friend of mine bought a BMW MY2020 and it still has a CD-player (it was an extra, but it was at least still available in 2020). I wouldn't be surprised if you could still order new car, today, with a CD player.

That's a fair point.

But I have to imagine that people who have a choice between AUX/bluetooth and CDs, and choose CDs are in the minority.

It's kind of a pain to install a CD burning app (which has long since atrophied from most music programs), plug in a removable drive, etc. I only do it because the alternatives are much worse.

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