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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)

#181

Post by kragen »

vel0city wrote: post #124
polygloty wrote: post #110

Earlier quoted context omitted.

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 d…

Stray strong magnets haven't been a problem for magnetic hard disks for 30 years. I don't think the fading of the magnetic domains on the disk is a problem over merely geological time scales either, though I'd be interested in finding out if I'm wrong. The mechanical parts are the big deal, and for recent disks (last 25 years) there are also concerns with onboard Flash or other EEPROM losing state.

Cosmic rays will eventually destroy anything that doesn't have an active repair process, including archival optical media, but the time scales are longer than when the Sun is predicted to swallow the Earth.

See also my comment yesterday: https://news.ycombinator.com/item?id=33116760

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

#182

Post by astrostl »

"DVD and BD (read-only, such as a DVD or Blu-ray movie) 10 to 20 years"

This is literally unbelievable to me. I have yet to encounter or hear about a single instance of a commercial disc failure, and that goes all the way back to double-sided DVDs in the old paper cases with a clip.

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

#183

Post by xerox13ster »

ahartmetz wrote: post #12

I should check my archive, but as of years ago, I have yet to find one bad disk. Anyone who cared could easily read up about it: writing at maximum speed produces marginal media. Writing at lower speed produces media with lower initial error rate and higher contrast, so much better longevity.

That was the kind of thing that kind of just seemed logical to me back then. I don't remember reading it anywhere, I think I just had the perception from VHS tape recording lengths.

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

#184

Post by babypuncher »

Recordable media is a crapshoot. Some discs are great, others are terrible. I wouldn't trust CD/DVD-R for long term media storage. These discs can also be harder on your optical drive. I've seen lots of Sega Dreamcast and Xbox consoles with prematurely worn out lasers because the owners mostly played burned games.

Pressed media has held up pretty well in my collection. I have CDs from the '80s that ripped perfectly as recently as last year. I've heard of discs with manufacturing defects that allow air to slowly reach the aluminum layer and oxidize them, but I have not seen this myself except on LaserDiscs.

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

#185

Post by devilbunny »

nordsieck wrote: post #95
jl6 wrote: 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…

If you’re in the US, try Crutchfield. Not the best prices if you happen to own an audio shop and already know how to do everything, but they include instructions on how to do everything (including take apart your dash) and phone support for the lifetime of the product, and for little or no extra include all the pieces needed to interface your aftermarket system with the stock harness.

I have a 2001 car that has been using a Bluetooth audio and hands-free setup from them for over ten years. (It’s old enough that “you can control your iPod with it if you plug it it” was a selling point.)

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

#186

Post by Snitch-Thursday »

at_a_remove wrote: post #158

I am surprised that we're still stuck at Blu-Ray levels of data storage on disc. I would have thought we would be up to a terabyte or so by now, but everything has stagnated. Tape remains expensive for the home data hoarder, and there is a point at which cloud storage becomes more expensive than tape.

I'd like Microsoft Project Silica to come to the market. Basically laser burning your data onto a cube of glass, like CD-Rs it is write once read many, but it can store so, so much more, and also once the bits are 'drilled' into glass...there is nothing to delaminate or stop reflecting. Is the glass scratched? No? Then a reading laser can see the bit state.

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

#187

Post by Snitch-Thursday »

mmwelt wrote: post #76
brazzy wrote: post #72

Earlier quoted context omitted.

> Although pre-industrial forms of paper (e.g. cotton paper, or papyrus) might have more long-term resistance than modern wood paper. The problem is not wood paper as such, it's production processes that leave some acidic substances in the paper, which causes it to become yellow and brittle on a timescale of a few decades. Acid-free paper will easily last hundreds of years, and is nowadays easily available.

So, perhaps use acid-free paper and print the data as QR codes using a laser printer?

Paperbak[1] is a good program for that.

[1] http://www.ollydbg.de/Paperbak/

[2] https://github.com/gxurma/PaperBak

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

#188

Post by augusto-moura »

xenadu02 wrote: post #55
yosito wrote: post #14

Earlier quoted context omitted.

"Hard drives" don't necessarily last any longer than a few years either.

Like DNA or living organisms: digital data has to be kept "live" to truly be secure, replicating itself somewhat regularly. Attempts to store it statically are cost-prohibitive or fail at much higher rates than claimed. Worse if the technology is on a down-hill trend because manufacturers focusing on quality are the first to go out of business (higher expenses in a shrinking market). You can ask the Floppy King about…

I'm not sure about this being the reality forever. Ever now and then we find some very old scripts or other ancient artifacts containing data from times already forgotten (at least on "basic" human language). If you want something to live eternity just etch the bytes into a stone or print it in some age resistent material.

Of course we can still hope on a easily writable medium that would be also very resistant to ageing.

Given the right context I even think that information produced by humans can outlive earth itself[1]

[1]: https://en.m.wikipedia.org/wiki/Voyager_Golden_Record

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

#189

Post by THENATHE »

So what is the real solution here?

I have a 2TB SSD in a caddy that I use for most of my stuff, then I have 2 disk RAID 1 array that is only used as periodic backup (only connected to power once a month) as well as having 2TB of cloud storage. I know I’m “good”, but it seems like there has to be a better way.

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