![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
thewayneIt all depends on the quality of the chips. The problem is obvious when you think of it. Memory is stored in transistors as an electrical charge in NAND flash cells, and even though they're called non-volatile (unchanging), slowly that electrical charge will drain, and with it, your data.
From the article: "...the cheapest SSDs, say those with QLC NAND, can safely store data for about a year of being completely unpowered. More expensive TLC NAND can retain data for up to 3 years, while MLC and SLC NAND are good for 5 years and 10 years of unpowered storage, respectively.
The problem is that most consumer SSDs use only TLC or QLC NAND, so users who leave their SSDs unpowered for over a year are risking the integrity of their data. The reliability of QLC NAND has improved over the years, so you should probably consider 2–3 years of unpowered usage as the guardrails. Without power, the voltage stored in the NAND cells can be lost, either resulting in missing data or completely useless drives." (I'm not sure if there's an easy way to see what kind of NAND chips are being used by your drives short of third-party utilities)
The nefarious aspect of this problem is that it may not be apparent. You might mount up a disused drive and everything appears fine, then you try to load a document or photo or whatever, and find it's irredeemably corrupted. It rotted in the middle and there's little that can be done. Other forms of rot might hit the directory itself and will be quite obvious when you look at the disk in Explorer or the equivalent. Some types of damage can be recovered, some cannot be.
This problem doesn't just apply to solid state drives: they use the same tech as thumb drives and camera memory cards of all types. The bit about the drive becoming completely useless is interesting, but the article doesn't clarify the subject. I suspect they're talking about rot hitting the config area of the drive which could make it unusable.
The article also talks about the 3-2-1 Backup Rule. Simply put, it's 3 copies of data on at least 2 different storage media, with 1 copy stored off-site. If you have a locker or desk at work, or a safe deposit box, these can be ideal places to store a backup. A storage locker can also work if it isn't exposed to extremes of weather. If you don't have absolute control of where your backup is stored, then you might want to look into encrypting it.
Conventional hard drives are not failure-proof, but they will theoretically last longer and don't normally have rot problems like this. They can have problems with stiction, where the read/write heads don't retract properly and actually stick to the platter. That doesn't happen much anymore, they're pretty good at reserving enough energy so if they're powered off abruptly they'll still retract to their park zone.
https://www.xda-developers.com/your-unpowered-ssd-is-slowly-losing-your-data/
https://hardware.slashdot.org/story/25/11/25/1511242/unpowered-ssds-in-your-drawer-are-slowly-losing-data
From the article: "...the cheapest SSDs, say those with QLC NAND, can safely store data for about a year of being completely unpowered. More expensive TLC NAND can retain data for up to 3 years, while MLC and SLC NAND are good for 5 years and 10 years of unpowered storage, respectively.
The problem is that most consumer SSDs use only TLC or QLC NAND, so users who leave their SSDs unpowered for over a year are risking the integrity of their data. The reliability of QLC NAND has improved over the years, so you should probably consider 2–3 years of unpowered usage as the guardrails. Without power, the voltage stored in the NAND cells can be lost, either resulting in missing data or completely useless drives." (I'm not sure if there's an easy way to see what kind of NAND chips are being used by your drives short of third-party utilities)
The nefarious aspect of this problem is that it may not be apparent. You might mount up a disused drive and everything appears fine, then you try to load a document or photo or whatever, and find it's irredeemably corrupted. It rotted in the middle and there's little that can be done. Other forms of rot might hit the directory itself and will be quite obvious when you look at the disk in Explorer or the equivalent. Some types of damage can be recovered, some cannot be.
This problem doesn't just apply to solid state drives: they use the same tech as thumb drives and camera memory cards of all types. The bit about the drive becoming completely useless is interesting, but the article doesn't clarify the subject. I suspect they're talking about rot hitting the config area of the drive which could make it unusable.
The article also talks about the 3-2-1 Backup Rule. Simply put, it's 3 copies of data on at least 2 different storage media, with 1 copy stored off-site. If you have a locker or desk at work, or a safe deposit box, these can be ideal places to store a backup. A storage locker can also work if it isn't exposed to extremes of weather. If you don't have absolute control of where your backup is stored, then you might want to look into encrypting it.
Conventional hard drives are not failure-proof, but they will theoretically last longer and don't normally have rot problems like this. They can have problems with stiction, where the read/write heads don't retract properly and actually stick to the platter. That doesn't happen much anymore, they're pretty good at reserving enough energy so if they're powered off abruptly they'll still retract to their park zone.
https://www.xda-developers.com/your-unpowered-ssd-is-slowly-losing-your-data/
https://hardware.slashdot.org/story/25/11/25/1511242/unpowered-ssds-in-your-drawer-are-slowly-losing-data
