Note: the worn drives were very worn. 128GB drive with 280TB written is ~2400 cycles. >5x it's 480x rating!
Even though it's a cheap drive, it's rated endurance wasn't really that low. 600 cycles (1200TBW/2TB) is pretty common for consumer SSD: that's higher than 480x but not vastly higher.
Glad folks are chiming in with the temperature sensitivity notes. I have parts coming in for a much bigger home-cloud system, and was planning on putting it in the attic. But it's often >110°F in the summer up there! I don't know how much of a difference that would make, given that the system will be on 24/7; some folks seem to say having it powered on should be enough, others note that usually it's during read that cells are refreshed.
Doing an annual dd if=/nvme0n1 of=/dev/zero bs=$((1024*1024)) hadn't been the plan, but maybe it needs to be!
I would never buy a no-name SSD. Did it once long ago and got bit, wrote a program to sequentially write a pseudorandom sequence across the whole volume then read back and verify, and proved all 8 Pacer SSD's I had suffered corruption.
That’s also fairly common for cheap ‘thumb drives’, as I understand it. I’ve been bitten by that before.
(Edit: Allegedly if you use low-numbered storage blocks you’ll be okay, but the advertised capacity (both packaging and what it reports to OS) is a straight-up lie.)
I wouldn't say it's controversial but I suspect most people don't know about it. There's been a lot of discussion about SSD write endurance but almost none about retention.
This is a known issue. You have to power up your SSDs (and flash cards, which are based on even more flimsy/cost optimized version of the same tech) every now and then for them to keep data. SSDs are not suitable for long term cold storage or archiving. Corollary: don't lose that recovery passphrase you've printed out for your hardware crypto key, the flash memory in it is also not eternal.
I'd at least just read all the used blocks on the drive. partclone is the most efficient that comes to mind, because it just copies used sectors. Just redirect to /dev/null.
Or leave the drive on all the time in an enclosure that keeps the nand cool (near room temperature).
Any decent SSD will background rewrite itself over time at an appropriate rate. Detecting that it needs to do so after 2 years in storage seems trickier to get right (no realtime clock) and trickier to test.
I’d be curious to know how quickly the drives in the article “heal” themselves if left plugged in. There’s nothing wrong with the hardware, even if they did lose a few sectors.
If you really want to create a correct protocol, you can accelerate nand aging by sticking them in an oven at an appropriate temperature. (Aging speedup vs temperature curves are available for most nand devices.)
A not-so-fun fact is that this even applies to modern read-only media, most notably Nintendo game carts. Back in the day they used mask ROMs which ought to last more or less forever, but with the DS they started using cheaper NOR or NAND flash for larger games, and then for all games with the 3DS onwards. Those carts will bit-rot eventually if left unpowered for a long time.
I've noticed a number of GBA carts I've picked up used (and probably not played in a long while) fail to load on the first read. Sometimes no logo, sometimes corrupted logo. Turning it off and on a couple of times solved the issue, and once it boots OK it'll boot OK pretty much every time after. Probably until it sits on the shelf for a long while.
The article states as much but to sum it all up as just that is leaving most of the good stuff out.
Perhaps the most interesting part of the experiment series has been just how much longer these cheap drives with tons of writes have been lasting compared to the testing requirements (especially with so much past write endurance on the one just now starting to exhibit trouble). Part of the impetus for the series seemed to be lots of claims on how quickly to expect massive problems without any actual experimental tests of consumer drives to actually back it up. Of course n=4 with 1 model of 1 brand drives but it's taken ~20x longer than some common assumptions to start seeing problems on a drive at 5x its endurance rating.
Please explain to me how is that supposed to work. For all I know the floating gate is, well, isolated and only writes (which SSDs don't like if they're repeated on the same spot) touch it through mechanisms not unlike MOSFET aging i.e. carrier injection.
Reading on the other hand depends on the charge in floating gate altering Vt of the transistor below, this action not being able to drain any charge from the floating gate.
According to a local expert (ahem), leakage can occur through mechanisms like Fowler-Nordheim tunneling or Poole-Frenkel emission, often facilitated by defects in the oxide layers.
If you at least read the data from the drive from time to time, the controller will "refresh" the charge by effectively re-writing data that can't be read without errors. Controllers will also tolerate and correct _some_ bit flips on the fly, topping up cells, or re-mapping bad pages. Think of it as ZFS scrub, basically, except you never see most of the errors.
It's a good idea to have a backup copy of the encryption keys. Losing signing keys is not a big deal but losing encryption keys can lead to severe data loss.
Clay works well. The Rosicrucian museum in San Jose has a cuneiform tax receipt stating that a goat was eaten by wolves, and therefore no tax is due on it.
This is similar, from 1634BC, but I don’t know what it says:
They say M-Discs are analogous to carving data onto stone. I have my doubts though. Searched the web and found posts claiming they are just regular Blu-ray discs now.
I mean, this reads as I expected it to: SSDs as cold storage are a risky gamble, and the longer the drive sits unpowered (and the more use it sees over its life), the less reliable it becomes.
Man, I’d (figuratively) kill for a startup to build a prosumer-friendly LTO drive. I don’t have anywhere near the hardware expertise myself, but I’d gladly plunk down the dosh for a drive if they weren’t thousands of dollars. Prosumers and enthusiasts deserve shelf-stable backup solutions at affordable rates.
I agree with the general sentiment, but just a headsup for those who might be unaware...
> thousands of dollars
I know this varies a lot based on location, but if you're stateside, you can get perfectly functional used LTO6 drives for $200-$500 that support 6TB RW cartridges that you can still buy new for quite cheap (20pk of 6TB RW LTO6 carts[0] for $60), much cheaper than any other storage medium I'm aware of and still reasonably dense and capacious still by modern standards. Sure it's 3-4 generations behind the latest LTO's, and you might need to get yourself a SAS HBA/AIC to plug it in to a consumer system (those are quite cheap as well, don't need to get a full RAID controller), but all in that's still quite an affordable and approachable cold storage solution for prosumers. Is there a reason this wouldn't work for you? Granted, the autoloader/enclosed library units are still expensive as all hell, even the hold ones, and I'd recommend sticking to quantum over IBM/HPE for the drives given how restrictive the later can be over firmware/software, but just wanted to put it out there that you don't necessarily need to spend 4 figures to get a perfectly functional tape solution with many many TB's worth of storage.
LTO6 capacity is 2.5TB. 6TB is "compressed" which these days is near worthless because data collections that size are likely to already compressed (example: video).
If the idea is to back up a hard drive, it's not nice to require big piles of tape to do it. Right now even the current LTO generation (LTO9, 18TB native capacity) can't back up the current highest capacity hard drives (28TB or more, not sure). In fact HDD is currently cheaper per TB (20GB drive at $229 at Newegg) than LTO6 tape ($30 for 2.5TB) even if the tape drive is free.
LTO would be interesting for regular users if the current generation drive cost $1000 or less new with warranty rather than as crap from ebay. It's too much of an enterprise thing now.
Also I wonder what is up with LTO tape density. IBM 3592 drives currently have capacity up to 50TB per tape in a cartridge the same size as an LTO cartridge, so they are a couple generations ahead of LTO. Of course that stuff is even more ridiculously expensive.
Correct, and absolutely worth noting, but point still stands. Had no intention of misleading, I called it a 6TB drive because that's what they're called (technically 6.25TB if we really want to get pedantic). Whether using LTO's compression or not, whether your data is already compressed or not, it's still a reasonable affordable, dense, reliable, approachable cold storage offering. Same is true even for LTO5.
It only starts to go sideways when you step up to LTO7 and above or try to get an autoloading all-in-one library unit. Though you can get lucky if you're patient/persistent in your bargain hunting.
You're both beating around the bush that is the core issue, though, and that's a lack of backup media that isn't a HDD for storing large amounts of data indefinitely, nevermind on a medium that doesn't have to be powered on every X interval to ensure it's still functional.
Prosumers/enthusiasts generally have three options for large-scale data backups (18TB+), and none are as remotely affordable as the original storage medium:
* A larger storage array to hold backups and/or versions as needed (~1.25x the $ cost of your primary array to account for versions)
* Cloud-based storage (~$1300/yr from Backblaze B2 for 18TB; AWS Glacier Deep Freeze is far cheaper, but the Egress costs per year for testing are comparable to B2)
* LTO drives ($3300 for an mLogic LTO-8 drive, plus media costs)
Of those, LTO drives are (presently) the only ones capable of having a stable "shelf life" at a relatively affordable rate. Most consumers with datasets that size likely aren't reading that data more than once or twice a year to test the backup itself, and even then maybe restoring one or twice in their lifetime. LTO is perfect for this operating model, letting users create WORM tapes for the finished stuff (e.g., music and video collections), and use a meager rotation of tapes for infrequent backups (since more routinely-accessed data could be backed up to cloud providers for cheaper than the cost of an associated daily LTO backup rotation). LTO is also far more resilient to being shipped than HDDs, making it easier to keep offline copies with family or friends across the country to protect your data from large-scale disasters.
It's the weird issue of making it cheaper than ever for anyone to hoard data, but more expensive than ever to back it up safely. It's a problem that's unlikely to go away anytime soon, given Quantum's monopoly on LTO technology and IBM's monopoly on drive manufacturing, making it a ripe market for a competitor.
I'd still love to see someone take a crack at it though. The LTO Consortium could use a shake-up, and the market for shelf-stable tape backup could do with some competition in general to depress prices a bit.
Endurance is proportional to programming temperature. In the video, when all four SSDs are installed at once, the composite device temperature ranges over 12º. This should be expected to influence the outcomes.
Tape is extremely cheap now. I booted up a couple laptops that have been sitting unpowered for over 7 years and the sata SSD in one of them has missing sectors. It had zero issues when shutdown.
Tapes are cheap, tape drives are expensive. Using tape for backups only starts making economic sense when you have enough data to fill dozens or hundreds of tapes. For smaller data sets, hard drives are cheaper.
HDDs are a pragmatic choice for “backup” or offline storage. You’ll still need to power them up, just for testing, and also so the “grease” liquefies and they don’t stick.
Up through 2019 or so, I was relying on BD-XL discs, sized at 100GB each. The drives that created them could also write out M-DISC archival media, which was fearsomely expensive as a home user, but could make sense to a small business.
100GB, spread over one or more discs, was plenty of capacity to save the critical data, if I were judiciously excluding disposable stuff, such as ripped CD audio.
If you don’t have a massive amount of data to backup, used LTO5/6 drives are quite cheap, software and drivers is another issue however with a lot of enterprise kit.
The problem ofc is that with a tape you need to also have a backup tape drive on hand.
Overall if you get a good deal you can have a reliable backup setup for less than $1000 with 2 drives and a bunch of tape.
But this is only good if you have single digit of TBs or low double digit of TBs to backup since it’s slow and with a single tape drive you’ll have to swap tapes manually.
LTO5 is 1.5TB and LTO6 is 2.5TB (more with compression) it should be enough for most people.
> But this is only good if you have single digit of TBs or low double digit of TBs
That's not so enticing when I could get 3 16TB hard drives for half the price, with a full copy on each drive plus some par3 files in case of bad sectors.
While the tape is relatively cheap, the tape drives are not. The new ones typically starts at 4K USD, although sometimes for older models the prices can drop below 2K.
Tape sucks unless you've got massive amounts of money to burn. Not only are tape drives expensive, they only read the last two tape generations. It's entirely possible to end up in a future where your tapes are unreadable.
There's a lot of LTO drives around. I strongly doubt there will be any point in the reasonable lifetime of LTO tapes (let's say 30 years) where you wouldn't be able to get a correct-generation drive pretty easily.
After I was bamboozled with a SMR drive, always great to just make the callout to those who might be unaware. What a piece of garbage to let vendors upsell higher numbers.
(Yes, I know some applications can be agnostic to SMR, but it should never be used in a general purpose drive).
Untested hypothesis, but I would expect the wider spacing between tracks in CMR makes it more resilient against random bit flips. I'm not aware of any experiments to prove this and it may be worth doing. If the HD manufacture can convince us that SMR is just as reliable for archival storage it would help them sell those drives since right now lots of people are avoiding SMR due to poor performance and the infamy of the bait-and-switch that happened a few years back.
> - make one yourself by hacking the firmware: https://news.ycombinator.com/item?id=40405578
Be careful when you use something "exotic", and do not trust drives that are too recent to be fully tested
Do you realize the irony of cautioning about buying off the shelf hardware but recommending hacking firmware yourself?
That "firmware hack" is just enabling an option that manufacturers have always had (effectively 100% "SLC cache") but almost always never use for reasons likely to do with planned obsolescence.
Converting a QLC chip into an SLC is not planned obsolescence. It’s a legitimate tradeoff after analyzing the marketplace that existing MTBF write lifetimes are within acceptable consumer limits and consumers would rather have more storage.
Edit: and to preempt the “but make it an option”. That requires support software they may not want to build and support requests from users complaining that toggling SLC mode lost all the data or toggling QLC mode back on did similarly. It’s a valid business decision to not support that kind of product feature.
If you care about long term storage, make a NAS and run ZFS scrub (or equivalent) every 6 months. That will check for errors and fix them as they come up.
All error correction has a limit. If too many errors build up, it becomes unrecoverable errors. But as long as you reread and fix them within the error correction region, it's fine.
What hardware, though? I want to build a NAS / attached storage array but after accidentally purchasing an SMR drive[0] I’m a little hesitant to even confront the project.
A few tens of TBs. Local, not cloud.
[0] Maybe 7 years ago. I don’t know if anything has changed since, e.g. honest, up-front labeling.
Nothing can really save you from accidentally buying the wrong model other than research. For tens of TBs you can use either 4-8 >20TB HDDs or 6-12 8TB SSDs (e.g. Asustor). The difference really comes down to how much you're willing to pay.
Good question. There seems to be no way to tell whether or not we're gonna get junk when we buy hard drives. Manufacturers got caught putting SMR into NAS drives. Even if you deeply research things before buying, everything could change tomorrow.
Why is this so hard? Why can't we have a CMR drive that just works? That we can expect to last for 10 years? That properly reports I/O errors to the OS?
zfs in mirror mode offers redundancy at the block level but scrub requires plugging the device
> All error correction has a limit. If too many errors build up, it becomes unrecoverable errors
There are software solutions. You can specify the redundancy you want.
For long term storage, if using a single media that you can't plug and scrub, I recommend par2 (https://en.wikipedia.org/wiki/Parchive?useskin=vector) over NTFS: there are many NTFS file recovery tools, and it shouldn't be too hard to roll your own solution to use the redundancy when a given sector can't be read
Not surprsing. Flash is for hot/warm storage, not for cold storage, but using literal bottom of the bargin-bin barrel no-name drives that are already highly worn really doesn't tell us anything. Even if these were new or in powered on systems for their whole life, I wouldn't have high confidence in their data retention, reliability or performance quite frankly. Granted, there is something to be said about using budget/used drives en masse and brute forcing your way to reliability/performance/capacity on a budget through shear scale, but that requires some finesse and understanding of storage array concepts, best-practices, systems and software. By no means beyond the skills of an average homelaber/HN reader if you're willing to spend a few hours of research, but importantly you would want to evaluate them as an array/bulk, not individually in that instance, else you lose context. That also typically requires a total monetary investment beyond what most homelabbers/consumers/prosumers are willing to invest even if the end-of-the-day TB/$ ratio ends up quite competitive.
There's also many many types of flash drives (well beyond just MLC/TLC/QLC), and there's a huge difference between no names, white labels, and budget ADATA's and the like, and an actual proper high end/enterprise SSD (and a whole spectrum in between). And No, 990/9100 Pro's from Samsung and other similar prosumer drives are not high end flash. Good enough for home gamers and most prosumers, absolutely! They would also likely yield significant improvements vs these levens in OP. I'm not trying to say those prosumer drives are bad drives. They aren't (The levens though, even new in box, absolutely are).
I'm merely saying that a small sample of some of the worst drives you can buy that are already beyond their stated wear and tear is frankly a poor sample to derive any real informed opinion on flash's potential or abilities. TL;DR: This really doesn't tell us much other than "bad flash is bad flash".
Even though it's a cheap drive, it's rated endurance wasn't really that low. 600 cycles (1200TBW/2TB) is pretty common for consumer SSD: that's higher than 480x but not vastly higher.
Glad folks are chiming in with the temperature sensitivity notes. I have parts coming in for a much bigger home-cloud system, and was planning on putting it in the attic. But it's often >110°F in the summer up there! I don't know how much of a difference that would make, given that the system will be on 24/7; some folks seem to say having it powered on should be enough, others note that usually it's during read that cells are refreshed.
Doing an annual dd if=/nvme0n1 of=/dev/zero bs=$((1024*1024)) hadn't been the plan, but maybe it needs to be!
Related: SSD as Long Term Storage Testing (132 points, 2023, 101 comments) https://news.ycombinator.com/item?id=35382252
(Edit: Allegedly if you use low-numbered storage blocks you’ll be okay, but the advertised capacity (both packaging and what it reports to OS) is a straight-up lie.)
What is the protocol you should use with SSDs that you’re storing? Should you:
- power up the SSD for an instant (or for some minutes?) without needing to read anything?
- or power up the cells where your data resides by reading the files you had created on the SSD?
- or rewrite the cells by reading your files, deleting them, and writing them back to the SSD?
The correct protocol is to copy the data to a more durable medium and store that.
Any decent SSD will background rewrite itself over time at an appropriate rate. Detecting that it needs to do so after 2 years in storage seems trickier to get right (no realtime clock) and trickier to test.
I’d be curious to know how quickly the drives in the article “heal” themselves if left plugged in. There’s nothing wrong with the hardware, even if they did lose a few sectors.
If you really want to create a correct protocol, you can accelerate nand aging by sticking them in an oven at an appropriate temperature. (Aging speedup vs temperature curves are available for most nand devices.)
Perhaps the most interesting part of the experiment series has been just how much longer these cheap drives with tons of writes have been lasting compared to the testing requirements (especially with so much past write endurance on the one just now starting to exhibit trouble). Part of the impetus for the series seemed to be lots of claims on how quickly to expect massive problems without any actual experimental tests of consumer drives to actually back it up. Of course n=4 with 1 model of 1 brand drives but it's taken ~20x longer than some common assumptions to start seeing problems on a drive at 5x its endurance rating.
Yeah. Paper is the best long term storage medium, known to last for centuries.
https://wiki.archlinux.org/title/Paperkey
It's a good idea to have a backup copy of the encryption keys. Losing signing keys is not a big deal but losing encryption keys can lead to severe data loss.
Carve it into stone if you it need to last longer than the Romans.
This is similar, from 1634BC, but I don’t know what it says:
https://archive.org/details/mma_cuneiform_tablet_impressed_w...
Man, I’d (figuratively) kill for a startup to build a prosumer-friendly LTO drive. I don’t have anywhere near the hardware expertise myself, but I’d gladly plunk down the dosh for a drive if they weren’t thousands of dollars. Prosumers and enthusiasts deserve shelf-stable backup solutions at affordable rates.
> thousands of dollars
I know this varies a lot based on location, but if you're stateside, you can get perfectly functional used LTO6 drives for $200-$500 that support 6TB RW cartridges that you can still buy new for quite cheap (20pk of 6TB RW LTO6 carts[0] for $60), much cheaper than any other storage medium I'm aware of and still reasonably dense and capacious still by modern standards. Sure it's 3-4 generations behind the latest LTO's, and you might need to get yourself a SAS HBA/AIC to plug it in to a consumer system (those are quite cheap as well, don't need to get a full RAID controller), but all in that's still quite an affordable and approachable cold storage solution for prosumers. Is there a reason this wouldn't work for you? Granted, the autoloader/enclosed library units are still expensive as all hell, even the hold ones, and I'd recommend sticking to quantum over IBM/HPE for the drives given how restrictive the later can be over firmware/software, but just wanted to put it out there that you don't necessarily need to spend 4 figures to get a perfectly functional tape solution with many many TB's worth of storage.
0: https://buy.hpe.com/us/en/storage/storage-media/tape-media/l...
If the idea is to back up a hard drive, it's not nice to require big piles of tape to do it. Right now even the current LTO generation (LTO9, 18TB native capacity) can't back up the current highest capacity hard drives (28TB or more, not sure). In fact HDD is currently cheaper per TB (20GB drive at $229 at Newegg) than LTO6 tape ($30 for 2.5TB) even if the tape drive is free.
LTO would be interesting for regular users if the current generation drive cost $1000 or less new with warranty rather than as crap from ebay. It's too much of an enterprise thing now.
Also I wonder what is up with LTO tape density. IBM 3592 drives currently have capacity up to 50TB per tape in a cartridge the same size as an LTO cartridge, so they are a couple generations ahead of LTO. Of course that stuff is even more ridiculously expensive.
It only starts to go sideways when you step up to LTO7 and above or try to get an autoloading all-in-one library unit. Though you can get lucky if you're patient/persistent in your bargain hunting.
Prosumers/enthusiasts generally have three options for large-scale data backups (18TB+), and none are as remotely affordable as the original storage medium:
* A larger storage array to hold backups and/or versions as needed (~1.25x the $ cost of your primary array to account for versions)
* Cloud-based storage (~$1300/yr from Backblaze B2 for 18TB; AWS Glacier Deep Freeze is far cheaper, but the Egress costs per year for testing are comparable to B2)
* LTO drives ($3300 for an mLogic LTO-8 drive, plus media costs)
Of those, LTO drives are (presently) the only ones capable of having a stable "shelf life" at a relatively affordable rate. Most consumers with datasets that size likely aren't reading that data more than once or twice a year to test the backup itself, and even then maybe restoring one or twice in their lifetime. LTO is perfect for this operating model, letting users create WORM tapes for the finished stuff (e.g., music and video collections), and use a meager rotation of tapes for infrequent backups (since more routinely-accessed data could be backed up to cloud providers for cheaper than the cost of an associated daily LTO backup rotation). LTO is also far more resilient to being shipped than HDDs, making it easier to keep offline copies with family or friends across the country to protect your data from large-scale disasters.
It's the weird issue of making it cheaper than ever for anyone to hoard data, but more expensive than ever to back it up safely. It's a problem that's unlikely to go away anytime soon, given Quantum's monopoly on LTO technology and IBM's monopoly on drive manufacturing, making it a ripe market for a competitor.
I'd still love to see someone take a crack at it though. The LTO Consortium could use a shake-up, and the market for shelf-stable tape backup could do with some competition in general to depress prices a bit.
If you have specific random IO high performance needs, you can either
- get a SLC drive like https://news.solidigm.com/en-WW/230095-introducing-the-solid...
- make one yourself by hacking the firmware: https://news.ycombinator.com/item?id=40405578
Be careful when you use something "exotic", and do not trust drives that are too recent to be fully tested: I learned my lesson for M2 2230 drives https://www.reddit.com/r/zfs/comments/17pztue/warning_you_ma... which seems validated by the large numbers of similar experiences like https://github.com/openzfs/zfs/discussions/14793
Tapes are also way more reliable than hard drives.
Up through 2019 or so, I was relying on BD-XL discs, sized at 100GB each. The drives that created them could also write out M-DISC archival media, which was fearsomely expensive as a home user, but could make sense to a small business.
100GB, spread over one or more discs, was plenty of capacity to save the critical data, if I were judiciously excluding disposable stuff, such as ripped CD audio.
The problem ofc is that with a tape you need to also have a backup tape drive on hand.
Overall if you get a good deal you can have a reliable backup setup for less than $1000 with 2 drives and a bunch of tape.
But this is only good if you have single digit of TBs or low double digit of TBs to backup since it’s slow and with a single tape drive you’ll have to swap tapes manually.
LTO5 is 1.5TB and LTO6 is 2.5TB (more with compression) it should be enough for most people.
That's not so enticing when I could get 3 16TB hard drives for half the price, with a full copy on each drive plus some par3 files in case of bad sectors.
Given the context of long term storage... why?
(Yes, I know some applications can be agnostic to SMR, but it should never be used in a general purpose drive).
Do you realize the irony of cautioning about buying off the shelf hardware but recommending hacking firmware yourself?
Edit: and to preempt the “but make it an option”. That requires support software they may not want to build and support requests from users complaining that toggling SLC mode lost all the data or toggling QLC mode back on did similarly. It’s a valid business decision to not support that kind of product feature.
All error correction has a limit. If too many errors build up, it becomes unrecoverable errors. But as long as you reread and fix them within the error correction region, it's fine.
A few tens of TBs. Local, not cloud.
[0] Maybe 7 years ago. I don’t know if anything has changed since, e.g. honest, up-front labeling.
[0*] For those unfamiliar, SMR is Shingled Magnetic Recording. https://en.m.wikipedia.org/wiki/Shingled_magnetic_recording
There might be SMR drives in there, but I suspect not.
Please don't tell everyone so we can still keep buying them? ;)
Good question. There seems to be no way to tell whether or not we're gonna get junk when we buy hard drives. Manufacturers got caught putting SMR into NAS drives. Even if you deeply research things before buying, everything could change tomorrow.
Why is this so hard? Why can't we have a CMR drive that just works? That we can expect to last for 10 years? That properly reports I/O errors to the OS?
zfs in mirror mode offers redundancy at the block level but scrub requires plugging the device
> All error correction has a limit. If too many errors build up, it becomes unrecoverable errors
There are software solutions. You can specify the redundancy you want.
For long term storage, if using a single media that you can't plug and scrub, I recommend par2 (https://en.wikipedia.org/wiki/Parchive?useskin=vector) over NTFS: there are many NTFS file recovery tools, and it shouldn't be too hard to roll your own solution to use the redundancy when a given sector can't be read
There's also many many types of flash drives (well beyond just MLC/TLC/QLC), and there's a huge difference between no names, white labels, and budget ADATA's and the like, and an actual proper high end/enterprise SSD (and a whole spectrum in between). And No, 990/9100 Pro's from Samsung and other similar prosumer drives are not high end flash. Good enough for home gamers and most prosumers, absolutely! They would also likely yield significant improvements vs these levens in OP. I'm not trying to say those prosumer drives are bad drives. They aren't (The levens though, even new in box, absolutely are).
I'm merely saying that a small sample of some of the worst drives you can buy that are already beyond their stated wear and tear is frankly a poor sample to derive any real informed opinion on flash's potential or abilities. TL;DR: This really doesn't tell us much other than "bad flash is bad flash".