Effects of sudden power loss on SSD's

vbimport

#1

Extreme Tech published an interesting article on the adverse effects of sudden power loss on both consumer and enterprise SSD’s. The article is based primarily on a report from the 11th Usenix Conference on File and Storage Technologies (FAST 13), which was published last February.

It seems unexpected power loss can lead to all sorts of errors in SSD’s, from corrupted data, all the way to complete failures of the drives.

Instructions from Crucial, regarding the disappearing M4 drives, were particularly strange. http://forum.crucial.com/t5/Solid-State-Drives-SSD-Knowledge/Why-did-my-SSD-disappear-from-my-system/ta-p/65215


#2

[QUOTE=Kerry56;2705653]
It seems unexpected power loss can lead to all sorts of errors in SSD’s,[/QUOTE]

Name a storage media about which this would not be true, particularly if the loss occurs during a write sequence.


#3

There are errors and then there is complete failure. Have you ever seen a spinning platter hard drive go tits up through a power failure alone? I’m sure its happened at some point, but I’ve never seen it personally.

Of the 15 drives they tested, one failed completely, and another lost a third of its capacity. Only one came through with no errors at all. Preventative measures built into the SSD’s didn’t seem to work as they should.

I’m not saying this is time for [I]the sky is falling[/I] panic. Its just an interesting study.


#4

Right, it really is an interesting study and I’d like to see manufacturers exposing and discussing more about it both openly and confidentially.

I had some HDD drives unable to function after power loss, but then they were just a few out of hundreds. Not that many HDDs died sudden deaths even when looking at some wild statistics published on Storage Review, or any other site. One OCZ SSD seemed to have problems and I just visited the importer’s office in Seoul to receive a replacement (after certain tests of the drive.)

I don’t agree with certain sentences in that article. After all, iPad and Galaxy tablets have SSD only, with no rotating HDD part. Apple announced the second-generation Retina MacBook Pro just a while ago. Some models come with 1TB PCIe SSD. The article’s author implies those MacBook Pro’s, along with all the Ativ’s and Mac Pro’s, are in extreme danger.


#5

I’m having a Deja Vu experience here.

I read about this earlier this year, perhaps even on the MyCE forums, and there are two things I remember:

  1. The power failures are synthetic: Power is cut to the drive instead of to the computer, so it’s not a realistic scenario and it might be a worse scenario than than the realistic one, since the power supply may cut the power to the drive more “gently” than this.

  2. The failure is not a result of one or a few sudden power cuts, but the result of 3000 power cuts.

This means that the failures are a result of unrealistic conditions and may or may not be a problem in real life.


#6

[QUOTE=DrageMester;2705703]

  1. The power failures are synthetic: Power is cut to the drive instead of to the computer, so it’s not a realistic scenario and it might be a worse scenario than than the realistic one, since the power supply may cut the power to the drive more “gently” than this.

  2. The failure is not a result of one or a few sudden power cuts, but the result of 3000 power cuts.

This means that the failures are a result of unrealistic conditions and may or may not be a problem in real life.[/QUOTE]Ditto, I was thinking along similar lines.


#7

I have had numerous power failures, along with Hurricane Sandy when the electricity surged and went down at least 10 times in 10 days, not one of my 14 SSDs were affected in any way.


#8

[QUOTE=alan1476;2705906]I have had numerous power failures, along with Hurricane Sandy when the electricity surged and went down at least 10 times in 10 days, not one of my 14 SSDs were affected in any way.[/QUOTE]

Same here. I’ve experienced losing files in all sorts of HDDs due to all kinds of failures and hangings but not with SSD except one case with a specific OCZ drive. “Never turn off PC when HDD is still running” has been the most important piece of advice to any novice user. Nobody worries about SSD failure in iPad and Ativ due to sudden battery failure or replacement .


#9

I remember hearing in school that hard drives are designed to guarantee that they will always finish writing a complete sector if they suddenly lose power. Supposedly they’re able to do this by utilizing their mechanical momentum. Maybe it’s a myth, I have no idea.

Beyond that, naturally there can be a break in the data when the drive stops running. File corruption that this might cause is a problem for the file system to protect against. But I can’t imagine how a power outage would damage the functionality of the disk. For that to happen, I think you’d have to have a more serious power event that caused electrical damage to the PCB.


#10

I’ve personally experienced HDD failure from a “power outage”, or more technically a power outage (and “surge”) that took out a power supply

Most people forget that when a computer power supply fails one of the possible failure modes is passing either high frequency square-wave power to the output or even simply passing sine wave input power to the output.

If this happens you are pretty much screwed.

I have personally seen destruction that could only be explained
by one or the other.

I have also experienced the effects of a lightning strike to a utility line
less than 150yards from my house (took out several TV’s VCR’s two
computers and my microwave oven) I actually suffered permanent
nerve damage in my right arm from this strike because I was on a
landline phone at the time (the phone came off even worse than my arm)

MY desktop runs on a UPS that runs off a surge suppressed outlet and I have a “whole house surge suppressor”.

But between my computer and the UPS there is another surge suppressed switchbox (Am I paranoid enough?)

I also have a pair of 1farad 16V capacitors on the power supply output rails (my computer runs for a good 15-20seconds after the power is physically cut to the supply

Added to that I have NO phones in my house that are not “cordless”
(I’ve personally been “zapped” twice, I don’t intend to allow it to happen again)

and my personal connection to my computer via my various “human interface devices” are ALL cordless. even my gaming joystick is cordless.
I say again, I don’t want to get zapped again.

So I’m not particularly worried about my system drive, my only SSD,
being exposed to outages or surges.


#11

Three words: Uninterruptible Power Supply…U…P…S…You kids should google them.

I refuse to use a computer without one.

The overwhelming majority of computer problems are caused by dirty and unreliable power.


#12

[QUOTE=Kenshin;2705690]I don’t agree with certain sentences in that article. After all, iPad and Galaxy tablets have SSD only, with no rotating HDD part. Apple announced the second-generation Retina MacBook Pro just a while ago. Some models come with 1TB PCIe SSD. The article’s author implies those MacBook Pro’s, along with all the Ativ’s and Mac Pro’s, are in extreme danger.[/QUOTE]

Because portable computing devices have de facto uninterruptible power supplies via their batteries, they’re much less susceptible to this specific problem than traditional desktops running off AC power.

For portable drives, the greater dangers are shocks, drops, and other sudden agitations due to the rough and tumble fact of being carried around.


#13

[QUOTE=negritude;2707567]Because portable computing devices have de facto uninterruptible power supplies via their batteries, they’re much less susceptible to this specific problem than traditional desktops running off AC power.

For portable drives, the greater dangers are shocks, drops, and other sudden agitations due to the rough and tumble fact of being carried around.[/QUOTE]

Very many smartphone users replace batteries regardless of what the SSD (in eMMC or whatever form factor) is doing. Perhaps the ones inside iPhone can be almost uninterruptible.