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The Reliability of Optical Disks

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Re: The Reliability of Optical Disks

#61

Post by TacticalCoder »

hlieberman wrote: post #30

If I am looking at a ~100 years timescale for preservation of documents, there are exactly two choices that I would consider. At the hundreds of years timescale, exactly one. Those are, in order: 1. Microfilm/microfiche 2. Ink on 100% cotton paper, or ink on vellum The properties of microfilm have been well studied. It requires no technology other than a magnifying glass to read, has a well over 500 year lifespan in…

I've got a printed book from 1575 here. Some pages at the beginning are in a bad shape but otherwise everything is still perfectly readable. I don't know which type of paper/ink it's using though. It's some book about plants: apparently one of the most printed book (after the bible) back in its days.

Re: The Reliability of Optical Disks

#63

Post by Wowfunhappy »

kevin_thibedeau wrote: post #29
spansoa wrote: post #24

Worth looking into Millennium Disc or M-DISC[0]. Apparently it's media that can last 1000 years. Thinking of buying two 50GB disks and putting some backup files on them when I have a few coins to drop. [0] https://en.wikipedia.org/wiki/M-DISC

BD M-disc is the same as a normal BD-R. The DVD M-disc is the only one worth considering for long time archival storage.

What makes you say that? The article appeared to find a significant difference in the reliability of standard BD-R's and M-Disc BD-R's.

Re: The Reliability of Optical Disks

#64

Post by xupybd »

codazoda wrote: post #40
blueflow wrote: post #13

Earlier quoted context omitted.

It matches my experience. Even decades-old CD-ROMs only fail when they are scratched or physically damaged, which you can prevent by keeping them in appropriate cases and always put them back after use.

My own experience is different. I had several brands of CD media that lasted less than 10 years. Many of them you could see the damage (cracks through the shiny layer). Some were dark blue, some a light blue. Almost all of them were bad. I had them stored in a light proof zipper pouch and stored at room temperature in a closet. Maybe something special happened to them over the years but very few worked. This would ha…

Some plastics can react with other plastics you have to be careful when storing long term in plastic bags for this reason. I'm not at all sure if this played a part in your CDs but it's possible.

Re: The Reliability of Optical Disks

#65

Post by jbverschoor »

digisign wrote: post #55
jbverschoor wrote: post #52

Earlier quoted context omitted.

About a month ago I went trough all my CD/DVDs. Factory disks were all good. But burned disks, especially the later cheaper ones mostly were either in bad condition, or not even recognized as media.

Brand? Treatment? I just grabbed one from my DJ days: TDK dated 1997-01-01: https://imgur.com/a/I7fokrx Listening to it now. We are… family ♪♫♪

After '00, the market was flooded with cheap discs.. Most of the bad ones were those.

Re: The Reliability of Optical Disks

#66

Post by mulmen »

digisign wrote: post #51

Would concur. I went thru all my old optical discs in ~2020 and moved all backups to 100GB Bluray. Went from dozens of discs to about three. Then I destroyed most of the old ones. (Didn't bother with some... does anyone need a copy of Netware 3.x or 4.x anymore? Even though it was so cool at the time.) All my CDs/DVDs burned from about '97 onwards were in perfect condition. I think one deteriorated, stuff I didn't ca…

At the turn of the century half of my personal CD collection was mix CDs from friends. Someone broke into my 25 year old Toyota and took the CD wallet, spare change and the car battery.

That was 9 years ago but I still wish I had a backup of those mix CDs.

Re: The Reliability of Optical Disks

#67

Post by chrisseaton »

Wowfunhappy wrote: post #62
chrisseaton wrote: post #10

Earlier quoted context omitted.

It's American English / British English isn't it?

Nope! Apple—of all companies—has a support article on this: https://support.apple.com/en-us/HT201697

> Nope!

https://en.m.wikipedia.org/wiki/Spelling_of_disc

> the spelling disk is more popular in American English, while the spelling disc is more popular in British English

Re: The Reliability of Optical Disks

#68

Post by dsego »

Wowfunhappy wrote: post #63
kevin_thibedeau wrote: post #29

Earlier quoted context omitted.

BD M-disc is the same as a normal BD-R. The DVD M-disc is the only one worth considering for long time archival storage.

What makes you say that? The article appeared to find a significant difference in the reliability of standard BD-R's and M-Disc BD-R's.

There are two types of BD-Rs, high to low & low to high. One is bad for long term and one is good (something something inorganic), but I forget which is which. From my research online bluray m-disc is just the better one but m-disc branded, apparently not the same stuff as the original m-disc DVD.

Re: The Reliability of Optical Disks

#69

Post by amelius »

jbverschoor wrote: post #52
digisign wrote: post #51

Would concur. I went thru all my old optical discs in ~2020 and moved all backups to 100GB Bluray. Went from dozens of discs to about three. Then I destroyed most of the old ones. (Didn't bother with some... does anyone need a copy of Netware 3.x or 4.x anymore? Even though it was so cool at the time.) All my CDs/DVDs burned from about '97 onwards were in perfect condition. I think one deteriorated, stuff I didn't ca…

About a month ago I went trough all my CD/DVDs. Factory disks were all good. But burned disks, especially the later cheaper ones mostly were either in bad condition, or not even recognized as media.

There are specialized companies who claim to be able to recover data from just about anything. Probably expensive, though.

Re: The Reliability of Optical Disks

#70

Post by neuralRiot »

robocat wrote: post #53
btrettel wrote: post #14

Earlier quoted context omitted.

> I wonder if like with floppy disks and drives, modern CD drives are less capable than old ones because they're no longer a premium product? When I ripped CDs I had from the 00s in 2019, I used an external Blu-ray drive from probably 2018 or so. Seemed to work okay; see [0]. I didn't have access to anything older so I can't compare but I think both new and old drives are probably good. [0] https://news.ycombinator.c…

Blu-ray discs use a red laser, and CD-ROMs use an infrared laser. The drives contain two laser diodes. Skip to 5:50 in https://www.youtube.com/watch?v=h9lbrr04XBQ

Blu-ray uses blue laser (blue-ray!) DVD uses red and CD infrared. Devices compatibles with the 3 mediums have 3 lasers on their optical pickup.
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