Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why I'm usually unnerved when modern SSDs die on us

utcc.utoronto.ca

Post reply on HN
Print view View original

51–60 of 258 posts

Re: Why I'm usually unnerved when modern SSDs die on us

#51

Post by pbhjpbhj »

blincoln wrote: post #47
Waterluvian wrote: post #5

"When a HD died early, you could also imagine undetected manufacturing flaws that finally gave way. With SSDs, at least in theory that shouldn't happen" Why shouldn't it? Isn't it just hardware too? "With spinning HDs, drives might die abruptly but you could at least construct narratives about what could have happened to do that" Why can't you do the same with SSDs? It feels like the author's main complaint is the fr…

Why shouldn't it? Isn't it just hardware too? In a mechanical hard drive, there are moving parts which can wear out due to friction, etc. SSDs are solid-state, so it seems like at least theoretically, it should be possible to build one that keeps working for decades. e.g. I have solid-state hardware from the 70s and 80s which still functions. I've always been a little mystified as to why SSDs' data areas wear out for…

On the subject of capacitor death. Is there a robotic device that can take in a circuit board and swap out all the [electrolytic] caps?

Re: Why I'm usually unnerved when modern SSDs die on us

#53

Post by astrodust »

darkmighty wrote: post #40
nneonneo wrote: post #29

A major problem with SSDs seems to be “firmware death” - where the flash chips are physically fine (or mostly fine), but the firmware (or firmware memory) has gotten corrupted due to some programming error, electrical glitch, or cosmic ray. I’ve had scores of older SSDs die after things like power outages and sudden shutdown events. This is super frustrating because the data is physically OK but the controller just i…

If that's the case, I wonder if controller failure could be prevented by ECC controller memory? Or would software failure recovery be sufficient to make a highly reliable controller?

With drives you used to be able to rip off a controller from an identical model and wire it back on to read the data.

With SSD or NVMe the controller isn't really a separate component you can just replace. Maybe it's possible to saw off the broken part and bodge-wire it to a working surrogate, but that would be extreme.

A tear-down of a broken SSD might reveal more about what could be done.

Re: Why I'm usually unnerved when modern SSDs die on us

#54

Post by ryanmercer »

ars wrote: post #9
Waterluvian wrote: post #5

"When a HD died early, you could also imagine undetected manufacturing flaws that finally gave way. With SSDs, at least in theory that shouldn't happen" Why shouldn't it? Isn't it just hardware too? "With spinning HDs, drives might die abruptly but you could at least construct narratives about what could have happened to do that" Why can't you do the same with SSDs? It feels like the author's main complaint is the fr…

> Why can't you do the same with SSDs? Because they don't die incrementally. Wtih a hard disk you'll get bad sectors, growing slowly over time. Or a head crash and then it's all dead. What could cause an entire SSD to die at once? I would totally understand bad sectors, but the whole thing at once? Where it doesn't even try to read existing data?

>What could cause an entire SSD to die at once?

A component failing? Electrical components fail. Sometimes it's a manufacturing defect, sometimes a design defect, sometimes something under or over-volted and it was enough to cause damage to any given component.

Could be an IC, could be a capacitor, could be a poorly laid trace. A poorly shielded RF source could even damage any number of components.

I mean, in theory a single high charge particle from that rare cosmic ray that reaches the surface of earth running full-steam-ahead through an IC could cause just the right amount of damage to make it fail although this would be an incredibly improbable scenario.

Same goes for HDDs, televisions, your clock radio, whatever.

Re: Why I'm usually unnerved when modern SSDs die on us

#55

Post by marcosdumay »

niftich wrote: post #21

Not that spinning HDDs are really any different, but SSDs are a perfect example of an entire computer that you attach to yours, and speak with through one of the (many) storage-oriented protocols. The device itself is a black box, and complex transformations take place between the physical persistence of the data and the logical structures that are exchanged on the wire. There are many layers of indirection, and many…

SSD's FLASH has plenty of wear and tear. It just has a different format from what happens to mechanical products. It's more similar to some metal that gets scratched on use, and will rust faster or slower depending on the amount of scratches.

What we have is that the software is currently less reliable than the memory. There is no fundamental reason for that, it's just that manufacturers put a huge amount of engineering work on reducing the wear, and not so much on programming practices.

Re: Why I'm usually unnerved when modern SSDs die on us

#56

Post by AnIdiotOnTheNet »

niftich wrote: post #21

Not that spinning HDDs are really any different, but SSDs are a perfect example of an entire computer that you attach to yours, and speak with through one of the (many) storage-oriented protocols. The device itself is a black box, and complex transformations take place between the physical persistence of the data and the logical structures that are exchanged on the wire. There are many layers of indirection, and many…

> but SSDs are a perfect example of an entire computer that you attach to yours, and speak with through one of the (many) storage-oriented protocols.

These days most of what we call a computer could be described this way. Even your compiled machine language is ultimately far more abstracted from what the processor actually does than it was on, say, a 6502.

Re: Why I'm usually unnerved when modern SSDs die on us

#57

Post by falcolas »

blincoln wrote: post #47
Waterluvian wrote: post #5

"When a HD died early, you could also imagine undetected manufacturing flaws that finally gave way. With SSDs, at least in theory that shouldn't happen" Why shouldn't it? Isn't it just hardware too? "With spinning HDs, drives might die abruptly but you could at least construct narratives about what could have happened to do that" Why can't you do the same with SSDs? It feels like the author's main complaint is the fr…

Why shouldn't it? Isn't it just hardware too? In a mechanical hard drive, there are moving parts which can wear out due to friction, etc. SSDs are solid-state, so it seems like at least theoretically, it should be possible to build one that keeps working for decades. e.g. I have solid-state hardware from the 70s and 80s which still functions. I've always been a little mystified as to why SSDs' data areas wear out for…

On 1): It's because each cell is essentially a consumable with a limited number of state transfers. It's similar in that way to how a solid state accellerometer still has a moving part inside it that can break or wear out over time.

EDIT: More reasons and methods for failure of "solid state" circuits and systems: https://news.ycombinator.com/item?id=14765868

Re: Why I'm usually unnerved when modern SSDs die on us

#58

Post by Severian »

olavgg wrote: post #35
Severian wrote: post #4

Call me crazy, but I don't think that a Crucial MX300 is the best choice for an enterprise worthy ZFS drive. I get what the author is concerned about, but I wouldn't be that surprised that a consumer level SSD failed in what sounds like a heavily used fileserver.

The most scary thing about using consumer grade SSD's in a file server is the amount of writes you do. For many use cases this is fine.

Very true. The slack reserve space, RAM buffer (and/or battery), and NAND process are the main things that make an enterprise drive.

The author doesn't specify a metric for writes, but based on the MX300 specs that I find, it can go up to 219 GB/day for the 2TB drives he uses, or 87 GB/day for a couple of the 525GB he still had. He doesn't specify though.

Re: Why I'm usually unnerved when modern SSDs die on us

#59

Post by marcosdumay »

Wowfunhappy wrote: post #18
NikolaeVarius wrote: post #8

Earlier quoted context omitted.

Well to be fair, there is an entire layer of abstraction at the SSD controller level that does tons of black box magic. It allows the OS to treat the SSD as another other storage device without letting the OS know what is going on. So the combination of non-moving parts (making it hard/impossible to debug via physical inspection) combined with a tons of wear leveling/misc magic can defo make it seem like SSD's are ma…

Is there a good reason why we use separate SSD controllers instead of letting the primary cpu handle it? The obvious reason is backwards compatibility, but as more of computing moves to SSDs, is this still relevant? ZFS has shown that removing layers of abstraction with regard to storage can be beneficial.

The controller makes it possible to get a standard bus and a pre-installed driver and use it to access any kind of memory from any manufacturer and any technology. It's the kind of convenience that makes people buy hardware - it's the kind of thing that made SATA and USB win. The alternative is that once in a while you plug a driver into your computer and it won't work.

Besides, I don't think manufacturers want to release the best practices for using their memory.

Re: Why I'm usually unnerved when modern SSDs die on us

#60

Post by AnIdiotOnTheNet »

Severian wrote: post #4

Call me crazy, but I don't think that a Crucial MX300 is the best choice for an enterprise worthy ZFS drive. I get what the author is concerned about, but I wouldn't be that surprised that a consumer level SSD failed in what sounds like a heavily used fileserver.

To be fair, the 'I' in RAID stands for 'inexpensive'.
Post reply on HN