Hacker News Reader

Comment by nayuki | Hacker News Reader

The article seems to talk about the same concept as a https://en.wikipedia.org/wiki/Bubblegram .

I like write-once optical storage media because it protects me from accidentally modifying or deleting files. Also I don't have to worry about HDD reliability issues like head crashes, circuit board failures, etc., and it's easier to keep optical discs in cold storage with zero maintenance effort.

While hard drives have been getting bigger and cheaper every year, is anyone else disappointed that write-once media technology has stagnated?

A rough timeline of when writable optical discs became popular and affordable: CD-R 700MiB (~2000); DVD+/-R (+DL) 4.7GB/8.5GB (~2005); BD-R 25GB (~2010); BD-R XL 100GB (~2015). Various holographic discs have been proposed but are vaporware. The problem today is that all these disc formats are tiny compared to the 10TB HDDs you can pick up easily.

View on HN

Raw storage per GB is also more expensive now compared to getting a giant hard drive. 100GB triple-layer BD-XL's are often ~$10/disk (~$0.10/GB). 10TB NAS-friendly HDD's can be had for ~$265 (~$0.0265). It sure was an interesting time where average desktop drives were only the size of a few DVDs which could be burned for less than a dollar. I hope improvements of commodity optical media happen but I think I'll be disappointed as consumers move to The Cloud. Chances are long term optical media archival will continue to move towards these esoteric implementations for massive corporations instead of something you can plug in to a normal computer (whatever a "normal computer" is in 20 years).

That said, there are other positives of going with write-once optical media. Magnetic or NAND media loses its charge over time, requiring refreshes to ensure data isn't lost. Its also more susceptible to outside EMI. Archive quality optical media is usually rated to safely store its contents for hundreds of years. I know I have cheap burned CDs from the 90s which still read with 100% accuracy, while most hard drives I have from that era have many errors and lots of corruption. Keep the media free from scratches, stored in the right temperature and humidity, and it'll probably outlive you without having to touch it.

My big issue is that optical media reliability isn’t where it needs to be for me to want to trust it for long term archival storage. Yes, some brands and media types are better than others, but it’s still enough a concern that I feel I can’t trust it in general.

What technology do you trust for long term archival storage? Magnetic and NAND media need refreshing for long term storage. I'm unaware of any kind of storage media which will last decades at a time on a shelf, other than printing it on acid-free paper with inorganic inks/dyes.

> What technology do you trust for long term archival storage?

Lots of copies on different platforms / storage formats sadly.

You can try M-DISC that's supposed to store data a thousand years. No idea if it keeps its promises, though.

https://de.wikipedia.org/wiki/M-DISC

English link https://en.wikipedia.org/wiki/M-DISC

I like optical media for the same reasons you indicate. Write once and have reasonable expectation it will last for a good long time. I do wish Optical media wasn't so stagnated as well. Write speeds could be improved by adding more laser heads to work in parallel on the disks, no reason for us to be stuck with a single head like vinyl had to for obvious reasons. That could increase disk R/W quite a bit and make it comparable to USB 2/3 but write once.

I'd love to get a holographic disk or heck an isolinear chip-shaped slab to write to because I like Star Trek.

When it comes to Blu-Ray read speeds, good drives will already outperform USB 2.0. 16x read speeds on Blu-Ray is 576Mbit, faster than USB 2.0's 480Mbit peak.

https://en.wikipedia.org/wiki/Blu-ray#Drive_speeds

I'm not so demanding when it comes to archival read/write speeds. Even if a drive writes 10 MB/s, it will crunch one terabyte in about a day. My gripe is that with small discs, you need to manually change discs and set up burns.

I am more than willing to leave my computer on overnight to write to a 1 TB optical disc with no human intervention. And this action is only for cold storage; HDDs are bigger anyway and I would have the data in hot storage if I needed to browse or edit it.

Reply on news.ycombinator.com