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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)

#121

Post by steveBK123 »

Interesting that it looks like Blu-Rays in all forms have much shorter longevity than the preceding DVD and CD formats. Presumably due to tighter tolerances required to fit more data on the same platter size?

I had switched to large format 50-100GB M-DISC BD-Rs a few years ago, but to be honest I'm often too lazy to bother with the process of burning discs for offline storage.

I should probably upgrade my NAS/external HDD&SDD stack again. I would advise anyone going the NAS route to think carefully and read reviews on RAID devices. It's probably safer & easier to keep 2 copies in 2 formats on 2 different media in the end. I have had numerous consumer grade NAS RAID devices fail to the point I almost find it an additional failure mode rather than level of safety. Fragility of consumer grade RAID reminds me there's a reason our employers hire storage engineers!

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

#122

Post by bitL »

squarefoot wrote: post #6

I've stopped using burned CDs and DVDs like 15 years ago, long before they were considered obsolete, after losing a huge amount of data, including multiple backups of projects. All of them were kept in their own case on a wall CD/DVD holder, no weights, no humidity, no excessive heat or any sun exposition. After only about 5 years like 30% of them were unreadable at all and others developed errors, so as soon as I re…

100GB M-DISCs are still pretty decent archival means. All photos/videos I've ever generated are roughly 1.2TB so that's 12 of those M-Discs.

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

#123

Post by steveBK123 »

mrfinn wrote: post #19

> BD-R (dye or non-dye, single layer or dual layer) 5 to 10 years > BD-R (non-dye, gold metal layer) 10 to 20 years > BD-RE (erasable Blu-ray) 20 to 50 years I find hard to believe that info. Seems to be sustained by a single study. That would mean that bluray (specially the BR-R format) is a pretty flawed technology.

My educated guess would be something along these two threads:

* Higher data density => tighter tolerance => same physical degradation is more catastrophic (DVD ~7x density of CD, BD-R ~20/10/5x DVD density = up to 140x CD density)

* Produced later and therefore like all consumer goods, less regard for durability and more regard for absolute cost optimization

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

#124

Post by vel0city »

polygloty wrote: post #110
darkwater wrote: post #29

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…

Isn't archiving on a HDD a more robust solution?

Depends on the quality of the archival media. Magnetic hard disks aren't without their own failure modes. The magnetic signals on the disk eventually fade causing errors. Motors and arms fail. Cosmic rays flip magnetic state. Or just stray strong magnets if you don't store it right.

Really good archival optical media isn't susceptible to the same cosmic ray it magnetic fade while reducing the chances of disc rot or delamination.

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

#125

Post by JoeAltmaier »

Print media is often considered 'more permanent' that other digital storage media. But consider: every courthouse I ever visited had records 'back to the fire', the time the records room burned. Every one.

Considering the flammability of paper multiplied by the probability of a fire annually gives you the means to come up with a mean-time-between-failure for paper records. And I'd guess it isn't very long - maybe 50 years to a century.

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

#126

Post by xattt »

pmontra wrote: post #42
darkwater wrote: post #29

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…

I recently sampled a CD-R from late 90s, mostly videos. I couldn't open a few files. Storage: inside home, temperature range from maybe 18 at night to 35 max. I'll give a try to ddrescue.

One thing that’s missing is discussion of specific disc drives. Even in the early 2000s, some were known to be picky and some were flawless.

It could be a case of using the original drive to read the media, versus some cost-cut version that’s on the market these days.

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

#127

Post by xattt »

JoeAltmaier wrote: post #125

Print media is often considered 'more permanent' that other digital storage media. But consider: every courthouse I ever visited had records 'back to the fire', the time the records room burned. Every one. Considering the flammability of paper multiplied by the probability of a fire annually gives you the means to come up with a mean-time-between-failure for paper records. And I'd guess it isn't very long - maybe 50…

Sprinklers, as well as waterless fire suppression systems, are fairly recent inventions so their mettle has not been really tested on the time scale of document archiving.

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

#128

Post by bluGill »

grayfaced wrote: post #105
danielheath wrote: post #88

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?

A fair number only fragments remain. Probably most, though I'm not an archaeologist.

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

#129

Post by bluGill »

grishka wrote: post #108
jefftk wrote: post #96

Earlier quoted context omitted.

How expensive is your housing per square foot? I suspect cloud storage is cheaper.

I don't know how common it is to own your living space in the US, but where I'm from, it is fairly common. And I don't think "how expensive per square foot" is applicable when you aren't renting. But either way, you won't be paying more in rent and/or utilities for having an extra box in your closet.

Unless that one box is the one that causing you to buy/rent more space to store things. In general storage space is very lumpy - people have a fair amount free until they don't and need to get more space - when you get more space you tend to get a lot more. (Of course downsize/decluttering is also an option)

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

#130

Post by MayeulC »

Kiro wrote: post #59

Never had a CD, DVD, SSD or HDD fail on me since the 90s. I'm almost starting to believe it's a myth.

You are lucky... And/or just don't have a large sample size. Of the multiple hundred CDs I've burned back in the day, some failed in just a few months. Admittedly, it was in tropical (high-humidity, high-temperature) settings.

As for HDDs, I lost about a quarter to a half, with the rest just being obsolete these days. I can definitely attest from personal experience that hard disks from the same series tend to fail at the same point (I had 3 WD blue HDDs in a single computer, as system, data, archival disks; the system one failed, so I moved the system to the data one, which failed a bit after; so I retired the third one; failures happened at about the same runtime according to SMART data).

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