Why I'm usually unnerved when modern SSDs die on us • Hacker News Board

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

#241

Post by daemin » Wed, Dec 12, 2018, 1:17 PM UTC

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…

This reminds me of a story that a lecturer told us at University. That at one point they distributed computations to the drive controllers of the connected (fridge sized) disk drives because they could do so much processing while waiting for the platters to spin into place.

So the whole story of a disk being a computer has been true for a long time.

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

#242

Post by pnutjam » Wed, Dec 12, 2018, 2:12 PM UTC

mkirklions wrote: post #44

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…

Does this explain why I often can access my 'dead' SSDs with my Ubuntu install rather than Windows? I havent run into this issue for ~4 years, so I'm not sure if this is a solved problem or I got lucky a few years back.

I have a laptop where the SSD wouldn't accept a Windows install, but worked fine with Linux. Months later, it took Windows with no issue...

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

#243

Post by 0db532a0 » Wed, Dec 12, 2018, 2:45 PM UTC

Dylan16807 wrote: post #236

0db532a0 wrote: post #152

Earlier quoted context omitted.

The electrons aren't shot through the insulation. They end up in the floating gate by quantum tunneling. The insulation by its name is non-conductive, and must be so that the electrons stay put. The degradation happens through general thermal wear.

Thermal wear? I thought it was mostly based on write cycles. How can that be 'thermal'?

The write cycles are realised by moving electrons through a material. This creates heat, which leads to gradual degradation of the material.

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

#244

Post by LeftTurnSignal » Wed, Dec 12, 2018, 3:06 PM UTC

yeukhon wrote: post #200

LeftTurnSignal wrote: post #145

Earlier quoted context omitted.

I've had moderate success with sticking failing HDs in the freezer overnight in hopes of getting it to spin one last time. Never tried baking a drive (ssd or hd), but I have with a red ring'd xbox360 mobo. Sometimes the "low tech" solutions still work.

Curious what is the rationale?

I don't know the technical side enough to give any real answer, but tossing them in the freezer (properly sealed of course) always seemed to help "loosen" them up enough to get data off.

I've also had some hard drives that you could bring back to life by giving them a firm knock with your knuckles too.

Doesn't really answer much, but it's a last ditch effort that has saved me more times than not.

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

#245

Post by jiveturkey » Wed, Dec 12, 2018, 4:50 PM UTC

pkaye wrote: post #91

I worked on SSD firmware for quite a long time and here is my perspective. Early flash used to fairly reliable with almost minimal error correction. However with increasing density, smaller processes and multi level cells, it has gone progressively less reliable and slower. Here are some of the things that we need to worry about: https://www.flashmemorysummit.com/English/Collaterals/Procee... To compensate for all th…

> Another problem is that the job while rewarding is not very lucrative.

Why is this a problem?

Let's not forget, we live in a capitalistic society. The job of the capitalists is to exploit labor. The cost of labor is a direct result of the market demand (or not) for a more complex or, by your point, a more robust product.

It need not simply be a market reaction, though. A vendor can create the market for a more complex/robust product. But still, their job is to exploit the available labor so if the people capable of such are available at a lower cost, so be it.

> I have a higher chance working on a web connected gadget to become a millionaire.

As others have noted, perhaps true but the numbers are so small it may as well also be zero. However, as you should now be pointedly aware, the perception doesn't match reality.

Question: do new grads (or let's say up to 3 years experience) working on SSD firmware, making $90k, have to clock in 60+ hours / week and live in insanely high cost regions where their $120k startup salary qualifies them for housing assistance programs and they have to live with at least one if not more roommates? Or is $90k (per another comment) quite good in relation to the total picture?

IOW, my guess is that you are not competing for talent on salary or total comp. My guess is you are competing on general industry attractiveness. The entire mindset around embedded vs web/consumer programming is different. So I think to frame it as a compensation problem is wrong, and by misframing it you will never "solve" it.

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

#246

Post by Dylan16807 » Wed, Dec 12, 2018, 7:44 PM UTC

0db532a0 wrote: post #243

Dylan16807 wrote: post #236

Earlier quoted context omitted.

Thermal wear? I thought it was mostly based on write cycles. How can that be 'thermal'?

The write cycles are realised by moving electrons through a material. This creates heat, which leads to gradual degradation of the material.

Does the individual gate get that much hotter than the rest of the device?

If I keep my SSD 40 degrees cooler with a freezer, will it last an indefinite number of write cycles?

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

#247

Post by 0db532a0 » Wed, Dec 12, 2018, 8:52 PM UTC

Dylan16807 wrote: post #246

0db532a0 wrote: post #243

Earlier quoted context omitted.

The write cycles are realised by moving electrons through a material. This creates heat, which leads to gradual degradation of the material.

Does the individual gate get that much hotter than the rest of the device? If I keep my SSD 40 degrees cooler with a freezer, will it last an indefinite number of write cycles?

I just looked this up, and it turns out I was completely wrong about how the wear is caused. Apparently it’s due to a build-up of electrons remaining in the floating gate over time, and not general thermal wear. It turns out that heating can even reverse this wear. Explained in this link: https://arstechnica.com/science/2012/11/nand-flash-gets-bake...

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

#248

Post by notatoad » Wed, Dec 12, 2018, 11:58 PM UTC

lisper wrote: post #108

notatoad wrote: post #97

Earlier quoted context omitted.

Physical devices don't have SLAs, because they aren't services. SSDs have the physical equivalent of an SLA, a warranty. I haven't seen stats, but in my experience the odds of an SSD dying within the warranty period is very very low. If you want your storage to have an SLA, storage service providers exist, and will be happy to give you an SLA if you're willing to pay. But it isn't cheap.

> Physical devices don't have SLAs Yes, I know that. That's why I said "essentially". > SSDs have the physical equivalent of an SLA, a warranty. There are two orthogonal issues. The first is what happens when a device fails. A warranty addresses that. The second is how does it fail. Does it fail all at once with no warning, no way to perform post-mortem diagnostics, and no way to recover the data? Or does it fail wit…

>Does it fail all at once with no warning, no way to perform post-mortem diagnostics, and no way to recover the data? Or does it fail with a gradual degradation of performance and capacity over time, and in a way that, if/when total failure occurs, the cause can be ascertained and the data still recovered somehow?

how does that have any relation to an SLA? An SLA is a promise of a certain amount of uptime, with financial penalty for the provider if not met. A warranty is a promise of a certain product lifespan, with a financial penalty for the provider if not met.

SLAs have nothing to do with providing diagnostic information.

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

#249

Post by vokep » Thu, Dec 13, 2018, 12:14 AM UTC

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?

There's a single wire in all computers, for some reason they always just have to include it, which if severed will completely disable the computer, as in, it won't even turn on, not even try to turn on.

That wire is the one delivering power. Point being, while things are so complicated that you often can have a lot going on and still try things, there are still single points of failure that can never be fully covered.

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

#250

Post by MrEldritch » Thu, Dec 13, 2018, 8:06 AM UTC

anticensor wrote: post #153

soneil wrote: post #88

Earlier quoted context omitted.

I'm just distrustful of drives. All storage is essentially cache, and should be treated like it. I'm of the opinion that harddrives don't actually function, they just maintain the illusion while they wait for a more interesting moment to die.

Why do their motors move, then? For making noise?

For scratching the platter, obviously.