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Comment by YokoZar | Hacker News Reader

From what I can find online, the lifetime of a BD-R disk is only 5-10 years. Those recordable Bluerays you're holding on to may _already_ have gone bad.

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I think that's much shorter than real life outcomes.

Just last week, I was looking for some old data. I dug through a small collection of cheap CD-R backups from 30 years ago (hard to believe the tech is that old!). Probably 12 discs in total. No problem physically reading any of them. The only issue is that one of them was recorded in an old pre-OSX Mac format that my Linux laptop struggled with, but I was able to access it on my 2015 MacBook.

I didn't want to sound like an advertisement, but I use M-disc media. It's basically Bluray, but should last a couple centuries. The M actually is for 'millennium', but I wouldn't bank on 1000 years.

I have a Verbatim M-DISC BD-R that I torture test. It was one of the first ones I burned. I burned it in 2018. I flex it all the time, use it as a coaster on my desk, leave it out on my patio in the sun for weeks at a time. I rinse it off with pool water and wipe it off with paper towels. It has yet to lose a single bit.

If this 20ish gigs of data hasn't had a single bit of corruption, I doubt most of the other discs in climate controlled storage in multiple locations have had much errors either.

There are many sources saying that BD-R discs should last decades if not a 100 years. One of the main reasons why BD M-Discs never took off was the fact that they didn't offer any substantial advantages over regular BD-Rs.

I also hope to last decades, so to me there is a world of difference between media that lasts 30 or 40 years, and media that lasts 100 or 200 years. For better or worse, as long as we both avoid accidents, an M-disc will outlast me.

From my research into it some time ago - BDXL quad layer(128GB) BD-Rs are made basically in the same technology as M-Disc, so they should last hundreds of years, so that's all I've been using for my archival needs so far. Getting them from Amazon japan is pretty cost effective too.

Curious why the media is more durable than CD-Rs which are known to degrade after 5-10 years (give or take).

It depends on the dye used. Older CD-Rs had a really bad dye formulation. Better formulations were created but most of us just bought blank disks based on what was cheapest not what dye was used.

Even the newer ones will still degrade quite rapidly in direct sunlight, so the method of storage is also important (spindles in your bookcase that get hit by sunlight = bad).

https://en.wikipedia.org/wiki/CD-R#Dyes

FWIW I archived all my CD-Rs and DVD-Rs when the oldest ones were just about 15 years old and aside from one ultra-cheap disc where the top was literally flaking off they all read fine in ddrescue.

I was part of an effort at my last job to archive some of the source code for our oldest projects(from the 90s), they were all on CDs stored in a vault with an external storage company, we retrieved the boxes and found that 1 in 5 discs didn't read at all. The blue verbatim discs had a 100% success rate, but any disc with that green hue underside was a toss up whether it would read or not. Interestingly though, over hundreds of discs I found that either the disc read and would rip correctly all the way, or it wouldn't work at all in the first place.

Practically all the CD-Rs I burned on good media have lasted over 20 years now. Only a few have had noticeable issues of the ones sold as "archive-quality" media.

Sure, almost all my cheap ones have died out, but even some of those are still pretty OK.

I have CD-Rs more than twice as old that work just fine. Would I place my bet on it? No. But it's not set in stone.

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