Recordable blu-ray discs have a reported lifespan of hundreds of years if left untouched, but the high-capacity ones (128GB) are not especially cheap right now and I assume the writing process is slow. The drives themselves may not be easy to come by in future decades. But they are your best bet for "I want my data to outlive my grandchildren."
For the rest of us, a USB spinning rust hard drive formatted as exFAT is going to be hard to beat. You'll be able to plug this into virtually any computer made in the next few decades (modulo a USB adapter or two) and just read it. They are cheap (even allowing for the rising cost of storage), fast, and most importantly, they are easy. The data is stored magnetically, so is not susceptible to degradation just from sitting like SSDs or flash drives are.
Of course, you should not store any important data on only ONE drive. The 3-2-1 backup rule applies to archives as well: 3 copies, 2 different media, 1 off-site.
I recently went through this exercise and settled on HFS+ over exFAT. Reliability seems a bit better with some edge cases, and I don’t expect I’ll be put into a situation where I’m not able to read HFS+ drives.
(Though probably not appropriate if you’re primarily not a mac user, or won’t be in the future.)
I decided to go with NTFS for the filesystem as it has journaling. Works fine on Linux, and obviously Windows. For macOS there are various add-ons that support NTFS, but my use case there is read-only.
Probably depends on what “consumer-friendly” entails, how it’s stored, and the quantity of data.
If we’re talking the average tech-illiterate to literate-but-cost-and-space-constrained person, probably Blu-Ray. A burner+reader combo with a stack of dual-layer discs is probably cost-effective. High-capacity HDDs would probably be equally effective if you can guarantee that they’re stored away from accidents and mishandling, but if it requires a SATA-to-USB adapter with assembly then it might possibly be out of reach for some consumers, and any risk of damage from movement could rule it out entirely.
If we’re talking tech-savvy consumers who don’t have the IT budget of a corporation, maybe LTO-5 or LTO-6 tapes could work. Tapes themselves are very affordable and have a good shelf lifespan. Used libraries can be had for under $600. The primary issues would be finding one with an interface that works with your existing equipment and software to support tape read and write.
Consumer? Apple or Google Photos or 'drive' functionality of either. The only real risk then is losing your account and Apple Photos has an option to keep them all locally on disk.
To be pedantic, the post you responded to asked about "storage medium", not storage services, which leads to the question of what storage medium they use and how long the services will be around.
Honestly: multiple copies of encrypted cloud storage. (Encryption just for privacy.) You need decentralized backups anyway. Alternatively, two NAS systems with some RAID variation in different locations that back up each other can be more cost-effective for large capacities.
You're talking about backups which you wouldn't normally need to keep for decades and will be powered on regularly anyway. If it's archival, such as family photos for your kids when they grow up, cloud storage can lose them if you die or go to prison or for whatever reason don't keep paying the bill.
If you go to prison, you can lose whatever media you have as well. I wouldn't rely on a single cloud storage provider, but mirror on multiple ones, and mirror on one or more local device as well, at least for the most important data. I wouldn't use physical media as primary backup copies today: long-term durability, and availability & support of matching peripherals are uncertain, and they don't make proper backups with redundancy easier, nor their verifiability.
For the kids, I'd rather make physical photo albums.
What's long-term? I have some dvd-rs that push 20-25 years and despite the plastic getting brittle they still work. I also have some ide drives that still work without problems after 40 years. I would rather aim for 20 years and upgrade the storage device if I still need to retain the data.
That's a thought I hadn't had. The plastic of the disk getting so brittle it shatters in the drive due to age. I wonder what's the embrittlement profile of polycarbonate stored in reasonable condition.
Brittleness is not a concern. "Disk rot" is. The dyes used to make writable DVD's were organic (AZO usually), and break down starting at around the 17 year mark (some earlier, if they were poorly made). They have some measure of redundancy built-in, so you may not notice right away. The discs begin to look a bit "cloudy" at first. Eventually they become unreadable.
Go with inorganic blu ray media if you want longevity. Most HTL blu rays made currently will last around 100 years if properly stored. If you need longer there are M-Disc's, but they are expensive and rumor has it that ALL verbatim 100Gb blu rays are essentially M-Discs with different labels these days.
For all practical purposes any Blu ray larger than 25Gb is probably inorganic HTL, but if you worry a lot you can buy more expensive "archival grade" discs from Japan as well that have been vettted and tested.
I've personally never noticed brittleness in old optical discs (unlike the polystyrene jewel cases, which often turn brittle). I don't think shattering is likely, but if it's a concern some optical drives allow limiting the maximum spin speed. If the drive supports it you can temporarily set it with the -x option of the "eject" command from util-linux.
Recordable blu-ray discs have a reported lifespan of hundreds of years if left untouched, but the high-capacity ones (128GB) are not especially cheap right now and I assume the writing process is slow. The drives themselves may not be easy to come by in future decades. But they are your best bet for "I want my data to outlive my grandchildren."
For the rest of us, a USB spinning rust hard drive formatted as exFAT is going to be hard to beat. You'll be able to plug this into virtually any computer made in the next few decades (modulo a USB adapter or two) and just read it. They are cheap (even allowing for the rising cost of storage), fast, and most importantly, they are easy. The data is stored magnetically, so is not susceptible to degradation just from sitting like SSDs or flash drives are.
Of course, you should not store any important data on only ONE drive. The 3-2-1 backup rule applies to archives as well: 3 copies, 2 different media, 1 off-site.
I recently went through this exercise and settled on HFS+ over exFAT. Reliability seems a bit better with some edge cases, and I don’t expect I’ll be put into a situation where I’m not able to read HFS+ drives.
(Though probably not appropriate if you’re primarily not a mac user, or won’t be in the future.)
I decided to go with NTFS for the filesystem as it has journaling. Works fine on Linux, and obviously Windows. For macOS there are various add-ons that support NTFS, but my use case there is read-only.
Probably depends on what “consumer-friendly” entails, how it’s stored, and the quantity of data.
If we’re talking the average tech-illiterate to literate-but-cost-and-space-constrained person, probably Blu-Ray. A burner+reader combo with a stack of dual-layer discs is probably cost-effective. High-capacity HDDs would probably be equally effective if you can guarantee that they’re stored away from accidents and mishandling, but if it requires a SATA-to-USB adapter with assembly then it might possibly be out of reach for some consumers, and any risk of damage from movement could rule it out entirely.
If we’re talking tech-savvy consumers who don’t have the IT budget of a corporation, maybe LTO-5 or LTO-6 tapes could work. Tapes themselves are very affordable and have a good shelf lifespan. Used libraries can be had for under $600. The primary issues would be finding one with an interface that works with your existing equipment and software to support tape read and write.
Consumer? Apple or Google Photos or 'drive' functionality of either. The only real risk then is losing your account and Apple Photos has an option to keep them all locally on disk.
To be pedantic, the post you responded to asked about "storage medium", not storage services, which leads to the question of what storage medium they use and how long the services will be around.
I've been a big fan of M-Disc BD-R.
Honestly: multiple copies of encrypted cloud storage. (Encryption just for privacy.) You need decentralized backups anyway. Alternatively, two NAS systems with some RAID variation in different locations that back up each other can be more cost-effective for large capacities.
You're talking about backups which you wouldn't normally need to keep for decades and will be powered on regularly anyway. If it's archival, such as family photos for your kids when they grow up, cloud storage can lose them if you die or go to prison or for whatever reason don't keep paying the bill.
If you go to prison, you can lose whatever media you have as well. I wouldn't rely on a single cloud storage provider, but mirror on multiple ones, and mirror on one or more local device as well, at least for the most important data. I wouldn't use physical media as primary backup copies today: long-term durability, and availability & support of matching peripherals are uncertain, and they don't make proper backups with redundancy easier, nor their verifiability.
For the kids, I'd rather make physical photo albums.
What's long-term? I have some dvd-rs that push 20-25 years and despite the plastic getting brittle they still work. I also have some ide drives that still work without problems after 40 years. I would rather aim for 20 years and upgrade the storage device if I still need to retain the data.
That's a thought I hadn't had. The plastic of the disk getting so brittle it shatters in the drive due to age. I wonder what's the embrittlement profile of polycarbonate stored in reasonable condition.
Brittleness is not a concern. "Disk rot" is. The dyes used to make writable DVD's were organic (AZO usually), and break down starting at around the 17 year mark (some earlier, if they were poorly made). They have some measure of redundancy built-in, so you may not notice right away. The discs begin to look a bit "cloudy" at first. Eventually they become unreadable.
Go with inorganic blu ray media if you want longevity. Most HTL blu rays made currently will last around 100 years if properly stored. If you need longer there are M-Disc's, but they are expensive and rumor has it that ALL verbatim 100Gb blu rays are essentially M-Discs with different labels these days.
For all practical purposes any Blu ray larger than 25Gb is probably inorganic HTL, but if you worry a lot you can buy more expensive "archival grade" discs from Japan as well that have been vettted and tested.
I've personally never noticed brittleness in old optical discs (unlike the polystyrene jewel cases, which often turn brittle). I don't think shattering is likely, but if it's a concern some optical drives allow limiting the maximum spin speed. If the drive supports it you can temporarily set it with the -x option of the "eject" command from util-linux.