M-DISC – DVD/Blu-ray compatible discs that may last up to 1000 years

Would like to hear more about the longevity of recordable blurays.

Speaking for myself, but: I think it's just lack of market demand.

I used to give people data on a disc -- first floppies, then CD-R, and eventually DVD-R. It got the job done, was often much faster than sorting out how to do it over the network (especially if they were already standing right there), and it was cheap-enough.

For a long time, when I wanted to carry some data from A to B, I'd just put it on some manner of round disc and take it with me. It worked well.

I'd also use them for local data storage at times when they were cheaper than on-line spinny-rust storage. Lots of us here remember having floppy disk indexes and stacks/binders of optical discs. (Some of us still have them.)

But it's been years since I've done anything at all with a disc and I never found a compelling-enough use for BD-R to begin with.

My car has two optical drives right there in the dashboard and I have no idea if either of them can play a CD or DVD full of MP3s. It also has a USB port for mass storage, bluetooth, an aux input, and HDMI (which I'll use I ever feel like getting around to making a lossless digital-domain streamer with librespot). I'm surprised to find myself stating that I'm not motivated at all to see if it can play an MP3 from a disc, but the lack of this motivation is real.

I feel remiss in saying that I don't recall the last time I saw my stash of new CD-Rs although I do think that I know exactly where the last spindle of DVD-R blanks is located.

I think I've even got a USB optical drive somewhere that I scored for free, and I suppose that it would work, but I've never actually used it. For anything, at all. I've had it for years.

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It seems obvious to say, but: I just do a lot of that stuff over the network these days. When I want to give someone some data, I just email it to them as an attachment -- even if they're standing right there. If it's a lot of data, I can upload it to Google Drive or ye olde Dropbox or something, and share it from there.

Or, pocket supercomputers: If two of us are using our new-fangled pocket computers and want to combine our high-res photos and videos at the end of an outing, stuff like Quick Share on Android (or Apple's AirDrop) can automatically stand up a fast, private, bespoke, temporary 802.11AX network in an instant and get that done at blazing speed without using any wires or external media at all.

When I still want to carry "a lot" of data from A to B, then: I've got thumb drives ranging from a few gigabytes to a half-terabyte. The latter holds the same as 20 single-layer BD-Rs, or ~100 DVD-Rs and is much friendlier to deal with.

For hoarding data at home, I just use hard drives. They're online. They're automatically snapshotted with ZFS to help prevent my own errors from deleting or corrupting stuff accidentally. The replaceable bits are replaceable. The more-unique bits also use RAIDZ2 and are additionally backed up every night with restic to somewhere else in the universe.

I really should add another copy (maybe using a tidy Raspberry Pi system on a shelf in a friend's workshop or something), and that copy really should use an independent backup method, but it's Good Enough and doesn't involve a single optical disc.

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It's still easy-enough to buy new optical blanks if I wanted them for something, and I used to use quite a lot of them...but I just don't want to use them at all anymore.

I've moved on.

Yeah in general the value proposition of Blu-Ray M-Discs makes less sense vs. DVDs because the standard BD-Rs are also inorganic. One thing the random person on Reddit (and the people parroting his/her claims) don't seem to have realized is that the Blu-Ray M-Discs have always been visually identical to standard BD-Rs. Here's a review from 2015 that mentions this: https://goughlui.com/2015/10/16/review-tested-verbatim-lifet...

> The disc itself does have a printable white top, but also features branding in the centre consisting of areas of clear hub. The underside looks pretty much the same as a normal BD-R, being metallic chocolate brown in colour. It is visually indistinguishable.

...

> This bought me to a realization – unlike DVD’s, almost all regular BD-R discs do not use organic dye recording layers. Only BD-R LTH type discs do, and they have been shown to have poor longevity. With one of the main reasons for causing disc failure no longer an issue, it seems possible that this disc is not materially special compared to a regular BD-R.

The review also mentions that the text on the disc packaging quotes a lifetime of several hundred years, so that hasn't changed either. The actual M-Disc testing certification mentioned in the review quotes a 95% CI expected lifetime of 530 years and a mean expected lifetime of 1,000 years (meaning only half the discs can be expected to last that long).

M-Disc isn't an open standard, so the criteria for what is and isn't an M-Disc aren't publicly known. I think it's entirely possible that standard inorganic BD-Rs pass whatever criteria are necessary to call something an "M-Disc", and that there's never been any real difference between a high quality BD-R and an M-Disc BD-R.

That misapplies systems thinking: It's necessary to have both the software and the hardware, so it is necessary to have the hardware.

By the above comment's reasoning, you wouldn't invest in hardware because you'll lack the software, and then you wouldn't invest in the software because you'll lack the hardware.

> Nothing we do today will be even remotely important in 1,000 years

The irony of quoting the work of a poet who died over 200 years ago is thick.