Ask HN: What do you think of BDXL (100GB disks)?
I still have a need to archive data and I'm thinking about getting a BDXL writer and some disks. Is this a dumb thing to do in 2025?
22 comments
Are you sure the physical media is suitable for archival purposes? Many discs degrade over time due to sunlight, oxidation, mechanical damages (scratches etc.) and such. I wouldn't count on them being readable in 5+ years unless the manufacturer has done accelerated aging tests and wants to vouch for their suitability.
It's also doubtful that BDXL readers are going to be available in the future. Physical discs are getting rarer and rarer.
It's also doubtful that BDXL readers are going to be available in the future. Physical discs are getting rarer and rarer.
There are dedicated types for archival called mdisc. Still made. Much more durable, don't mind heat, sun, moisture.
Pretty impressive! http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www...
None of the ones on their official site seem to be available though? They all link to out of stock Amazon pages.
None of the ones on their official site seem to be available though? They all link to out of stock Amazon pages.
My local amazon shows 5 offers at least after simple "m-disc" search. And they work, got them twice recently.
It's not a grocery store buy but it's there.
It's not a grocery store buy but it's there.
Wow, so many weird things said so far in comments...
It is absolutely a good idea, but with some minor tweaks and for the right use case.
It's a great idea if you want to have modern hardware that is not very expensive and predictable media that will be readable after decades. And preferably a lot of pacience due to max 125GB on each disc, or low space size requirements. Discs ain't cheap, though!
For regular backups (even seldom, like half a year) I'd still go for HDDs, as they are available at around 13USD per TB. Also USB drive enclosures are as cheap as $20 so you can store them with drives. But drives will fail if you leave them with no power for a few years.
But if your archive is supposed to be one time (no often archival of the same content with minor changes), or you want to store that for many years, maybe decades, discs can be the easiest reliable way.
Standard discs won't guarantee longevity. They are sensitive to heat and moisture. Use m-discs for that. You can get them at 125GB for around $20 a piece. So MUCH more expensive than HDDs. But these will hold up for decades, don't mind humidity and even high heat.
Compatible drives are at around $100, like Verbatim I have. There are modern ones, still. With full power via USB-c, quiet, supported by popular software.
It's easy to store a drive (and even an old usff computer) in some box next to your discs, in your off-site place.
I find it more likely to be usable and better chance of being available after many years, compared to, for instance, decommissioned tape drive readers that some homelabers like to use. Also much cheaper.
Search for m-discs tests on YouTube. There are some hilarious tests there where a guy compares them with standard disks by leaving them outside during sun and rain for days, digging them in dirt, washing with soap like a plate, burning with cigarette lighter etc.
Spoiler alert: m-discs work like charm after that. Standard ones won't even spin properly.
It is absolutely a good idea, but with some minor tweaks and for the right use case.
It's a great idea if you want to have modern hardware that is not very expensive and predictable media that will be readable after decades. And preferably a lot of pacience due to max 125GB on each disc, or low space size requirements. Discs ain't cheap, though!
For regular backups (even seldom, like half a year) I'd still go for HDDs, as they are available at around 13USD per TB. Also USB drive enclosures are as cheap as $20 so you can store them with drives. But drives will fail if you leave them with no power for a few years.
But if your archive is supposed to be one time (no often archival of the same content with minor changes), or you want to store that for many years, maybe decades, discs can be the easiest reliable way.
Standard discs won't guarantee longevity. They are sensitive to heat and moisture. Use m-discs for that. You can get them at 125GB for around $20 a piece. So MUCH more expensive than HDDs. But these will hold up for decades, don't mind humidity and even high heat.
Compatible drives are at around $100, like Verbatim I have. There are modern ones, still. With full power via USB-c, quiet, supported by popular software.
It's easy to store a drive (and even an old usff computer) in some box next to your discs, in your off-site place.
I find it more likely to be usable and better chance of being available after many years, compared to, for instance, decommissioned tape drive readers that some homelabers like to use. Also much cheaper.
Search for m-discs tests on YouTube. There are some hilarious tests there where a guy compares them with standard disks by leaving them outside during sun and rain for days, digging them in dirt, washing with soap like a plate, burning with cigarette lighter etc.
Spoiler alert: m-discs work like charm after that. Standard ones won't even spin properly.
I don't trust any particular media to remain available or usable long term, either due to degradation or hardware availability. BD in particular has a very uncertain future.
I had to read a 20 year old Ultra320 HDD last weekend, and I had to dust off an old Sun workstation to do that.
I've been using LTO tape for many years, trailing a few generations for cost reasons.
Every couple of years, I read the data from my old tapes and migrate it to new tapes of the next generation, as the cost comes down.
I only have about 500GB of stuff that I particularly want to keep, mostly photographs and very short videos, along with copies of various personal documents that would be tiresome to replace. The 1.5TB provided by LTO5 is more than plenty for my own needs.
I had to read a 20 year old Ultra320 HDD last weekend, and I had to dust off an old Sun workstation to do that.
I've been using LTO tape for many years, trailing a few generations for cost reasons.
Every couple of years, I read the data from my old tapes and migrate it to new tapes of the next generation, as the cost comes down.
I only have about 500GB of stuff that I particularly want to keep, mostly photographs and very short videos, along with copies of various personal documents that would be tiresome to replace. The 1.5TB provided by LTO5 is more than plenty for my own needs.
Interesting question. My strategy for archival backups has been:
- local nas with decent redundancy
- a single external hard drive
- rclone everything to B2
so a lot of redundancy at relatively little cost. I have less than 100Tb but more than 20, so 100Gb would be too small..
- local nas with decent redundancy
- a single external hard drive
- rclone everything to B2
so a lot of redundancy at relatively little cost. I have less than 100Tb but more than 20, so 100Gb would be too small..
The only thing I really want to back up are photos and documents and it’s probably < 200GB.
Anything else digital (like games, movies, music, books, …) I could buy again if I really wanted another copy.
Anything else digital (like games, movies, music, books, …) I could buy again if I really wanted another copy.
Go for it. Perfect use case. But make sure to buy mdiscs, not just standard bdxl.
Much more expensive, but makes sense for that use case.
Much more expensive, but makes sense for that use case.
Optical media costs more per GB/TB than hard disks. It’s lower capacity and slower so there’s more hassle swapping discs. One time use media generates trash when the data on the disc is obsolete. Discs are a better fit when the use case calls for read only access or physical copies cheap enough to literally hand out. Such as ransomware resistance or evidence chain of custody. For offline copies you could just be diligent in unplugging external hard drives and testing backups.
BDXL is so expensive and low capacity. It seems totally unviable.
I thought Sony's 5.5 TB Optical Disc Archive looked cool but it was probably crazy expensive and AFAIK it's now discontinued.
I thought Sony's 5.5 TB Optical Disc Archive looked cool but it was probably crazy expensive and AFAIK it's now discontinued.
slower so there’s more hassle swapping discs. One time use media generates trash when the data on the disc is obsolete. Discs are a better fit when the use case calls for read only access or physical copies cheap enough to literally hand out. Such as ransomware resistance or evidence chain of custody. For offline copies you could just be diligent in unplugging external hard drives and testing backups.
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I would think that tape would be better for archival storage. My experience has been that the writeable optical media does not hold up well long term.
Tape needs expensive and hard to get drives. It's a gamble if that will be replaceable in many years, if it's already an expensive journey today. USB-C disc writer works with any modern system and is available new at reasonable price. Tech is well known.
Plus you archive on dedicated disc type for archival which is much more durable.
Plus you archive on dedicated disc type for archival which is much more durable.
> Tape needs expensive and hard to get drives
Expensive to buy new, but definitely not hard to get.
I paid $80 for my low hour LTO5 drive at a government auction. Tapes (1.5TB raw) are $15 each new.
There are hundreds of used drives on eBay for relatively little money.
Expensive to buy new, but definitely not hard to get.
I paid $80 for my low hour LTO5 drive at a government auction. Tapes (1.5TB raw) are $15 each new.
There are hundreds of used drives on eBay for relatively little money.
> but definitely not hard to get
very subjective. Anything at that price range doesn't exist in my region at all. Also consider if there will be a government auction next time your drive fails. I found just one offer for $500 now.
My personal "final straw" was also, that nothing that I was able to actually buy or afford (reasonably, so not $1000+) required me to have at least a full desktop to throw it in and often drivers were "windows only, but there should be something for linux somewhere". Simple usb makes it much smaller and easier.
very subjective. Anything at that price range doesn't exist in my region at all. Also consider if there will be a government auction next time your drive fails. I found just one offer for $500 now.
My personal "final straw" was also, that nothing that I was able to actually buy or afford (reasonably, so not $1000+) required me to have at least a full desktop to throw it in and often drivers were "windows only, but there should be something for linux somewhere". Simple usb makes it much smaller and easier.
Being out of your budget isn't the same thing as being hard to get.
As far as drivers are concerned, SCSI tape devices have been in the Just Works(tm) category on just about every UNIX-like platform (including Linux) for the last 40 years.
Everyone's needs are different. Use what works for you.
As far as drivers are concerned, SCSI tape devices have been in the Just Works(tm) category on just about every UNIX-like platform (including Linux) for the last 40 years.
Everyone's needs are different. Use what works for you.
I think my age gives me a romantic attraction to the idea of BDXL. Engineering brain says "most likely, no."
Per GB, spinning rust is faster, cheaper, more mature, physically smaller, less fiddly, easier to obtain from Walmart at 10pm Tuesday night, and doesn't require special hardware made by a handful of manufacturers only in a short window of time.
As a small-run distribution medium, BDXL might be the right technology.
All with the caveat that BDXL might be an improvement over an existing archive practice. For clarity not archiving is not an existing archive practice and BDXL is not going to transform anyone into the kind of person who systematically archives their work...
...you will use BDXL as much as you used floppies, CDR, Zip, etc. Good luck.
Per GB, spinning rust is faster, cheaper, more mature, physically smaller, less fiddly, easier to obtain from Walmart at 10pm Tuesday night, and doesn't require special hardware made by a handful of manufacturers only in a short window of time.
As a small-run distribution medium, BDXL might be the right technology.
All with the caveat that BDXL might be an improvement over an existing archive practice. For clarity not archiving is not an existing archive practice and BDXL is not going to transform anyone into the kind of person who systematically archives their work...
...you will use BDXL as much as you used floppies, CDR, Zip, etc. Good luck.