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Unpowered SSDs slowly lose data

xda-developers.com

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Re: Unpowered SSDs slowly lose data

#321

Post by asdefghyk »

I note , CHEMICAL reactions proceed faster with heat. So this why data retention is longer if device is in "...cold storage.." (This situation is also know with old photographic film , if stored in low temperatures it can last cira 100 years, but if stored at much higher room? temperatures , the film deterioration is much faster )

In SSD drives digital bits are stored as a electrical charge amount for each "cell".

I suspect these cells have been decreased in size to provide much larger numerically increased SSD storage amounts. The decreased cell size means the charge decreases below needed amount faster and ssd becomes unreliable.

MORE IMPORTANTLY - I also contend the SSD CHIP DESIGNERS would have/SHOULD HAVE been aware of this size effect and the decreased SSD reliability was not publicised OR specified for the product data sheets.

Presently I'm looking for articales that prove my suspicions or assertions

Re: Unpowered SSDs slowly lose data

#322

Post by asdefghyk »

From the above linked articale

"... Your SSD data isn't as permanent as you think Even 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. ..."

RE "...QLC NAND, can safely store data for about a year of being completely unpowered...."

QLC Nand only reliably stores data for only a year .

This would be within the warranty period for some products.

This information should be more clearly shown to product purchasers.

Re: Unpowered SSDs slowly lose data

#323

Post by asdefghyk »

lazide wrote: post #255
jeremyvisser wrote: post #218

Earlier quoted context omitted.

Here’s the thing. That SSD controller is the interface between you and those blocks. If it decides, by some arbitrary measurement, as defined by some logic within its black box firmware, that it should stop returning all blocks, then it will do so, and you have almost no recourse. This is a very common failure mode of SSDs. As a consequence of some failed blocks (likely exceeding a number of failed blocks, or perhaps…

Yes, and? HDD controllers dying and head crashes are a thing too. At least in the ‘bricked’ case it’s a trivial RMA - corrupt blocks tend to be a harder fight. And since ‘bricked’ is such a trivial RMA, manufacturers have more of an incentive to fix it or go broke, or avoid it in the first place. This is why backups are important now; and always have been.

RE "....This is why backups are important now; and always have been..."

Still a big problem if backup is to the "..same technology..."

Re: Unpowered SSDs slowly lose data

#324

Post by lazide »

mort96 wrote: post #320
lazide wrote: post #314

Earlier quoted context omitted.

Not as far as I can tell, where intended is ‘as any user would reasonably expect’. Bricking the drive (can’t even read) because of too many errors is not what most users would ever want. Some would (enterprise maybe), but even then they’d want deterministic data deletes too, which doesn’t sound like are happening.

You can argue that controllers shouldn't behave that way. But they do, it's not a bug, and it's not a dead controller. It's a perfectly functional controller's response to dead blocks.

Cite? By definition it appears to not meet the definition of ‘functional’.

Re: Unpowered SSDs slowly lose data

#325

Post by userbinator »

DoesntMatter22 wrote: post #290
userbinator wrote: post #147

Earlier quoted context omitted.

LCD tvs from 2012 and 2022 just went kaput for no reason. Most likely bad capacitors. The https://en.wikipedia.org/wiki/Capacitor_plague may have passed, but electrolytic capacitors are still the major life-limiting component in electronics.

Looks like that plague stopped in 2007? I have a 8 year old LCD that died out of nowhere as well, So I'm guessing wouldn't be affected by this. Could still be a capacitor issue though

Bad caps are still a common occurrence:

https://www.badcaps.net/forum/troubleshooting-hardware-devic...

Re: Unpowered SSDs slowly lose data

#326

Post by coldtea »

lazide wrote: post #324
mort96 wrote: post #320

Earlier quoted context omitted.

You can argue that controllers shouldn't behave that way. But they do, it's not a bug, and it's not a dead controller. It's a perfectly functional controller's response to dead blocks.

Cite? By definition it appears to not meet the definition of ‘functional’.

The definition of functional in the context of the discussion is that in works in the way the manufacture explicitly designed it work, in a standard industry practice fashion, not as an unforeseen bug or malfunction.

Not some abstract notion.

Re: Unpowered SSDs slowly lose data

#327

Post by lazide »

coldtea wrote: post #326
lazide wrote: post #324

Earlier quoted context omitted.

Cite? By definition it appears to not meet the definition of ‘functional’.

The definition of functional in the context of the discussion is that in works in the way the manufacture explicitly designed it work, in a standard industry practice fashion, not as an unforeseen bug or malfunction. Not some abstract notion.

So not enumerating as a drive, and not allowing you to read even valid blocks is ‘working’?

Re: Unpowered SSDs slowly lose data

#328

Post by lazide »

asdefghyk wrote: post #323
lazide wrote: post #255

Earlier quoted context omitted.

Yes, and? HDD controllers dying and head crashes are a thing too. At least in the ‘bricked’ case it’s a trivial RMA - corrupt blocks tend to be a harder fight. And since ‘bricked’ is such a trivial RMA, manufacturers have more of an incentive to fix it or go broke, or avoid it in the first place. This is why backups are important now; and always have been.

RE "....This is why backups are important now; and always have been..." Still a big problem if backup is to the "..same technology..."

That’s why 3-2-1 is not just a good idea.

Re: Unpowered SSDs slowly lose data

#329

Post by mafuy »

ianburrell wrote: post #288
leo_e wrote: post #234

We learned this the hard way with "cold" backups stored in a literal safe. We treated NVMe drives like digital stone tablets. A year later, we tried to restore a critical snapshot and checksums failed everywhere. We now have a policy to power-cycle our cold storage drives every 6 months just to refresh the charge traps. It's terrifying how ephemeral "permanent" storage actually is. Tape is annoying to manage, but at…

I think we should stop considering flash as permanent storage. It is temporary storage that keeps working as long as given power. I wish there was archival storage something long-lasting and large capacity. That would make a good complement to flash for writing backups and long-lasting data.

How much do you wish it? A modern LTO tape drive is 4000$ or so, plus tapes for 5$ per TB.

Re: Unpowered SSDs slowly lose data

#330

Post by coldtea »

lazide wrote: post #327
coldtea wrote: post #326

Earlier quoted context omitted.

The definition of functional in the context of the discussion is that in works in the way the manufacture explicitly designed it work, in a standard industry practice fashion, not as an unforeseen bug or malfunction. Not some abstract notion.

So not enumerating as a drive, and not allowing you to read even valid blocks is ‘working’?

Yes, same as a facility self-destructing, if it was programmed to do so, is working as per its spec.
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