3 ms·

All I have seen is not having rotational vibration sensors. https://www.tomshardware.com/news/seagate-hdd-failure-lawsuit-3tb,31118.html https://www.tomshardwa

by doikor 5y ago

All I have seen is not having rotational vibration sensors. https://www.tomshardware.com/news/seagate-hdd-failure-lawsuit-3tb,31118.html https://www.tomshardware.com/news/seagate-hdd-failure-lawsui... > The Seagate 3 TB models failed at a higher rate than other drives during the Backblaze deployment, but in fairness, the Seagate drives were the only models that did not feature RV (Rotational Vibration) sensors that counteract excessive vibration in heavy usage models -- specifically because Seagate did not design the drives for that use case.

daneel_w 5y ago
Do drives in this type of stationary assembly (i.e. a server rack or a stationary PC) ever trigger their vibration protection? Barring of course during a bit of bumping in the server rack. I mean, these drives are not sitting in laptops. I have a hard time thinking the lack of this feature bears any weight on the huge failure rates Backblaze and discrete customers saw, though I'd accept the argument if there was a 2.5" laptop model of that drive seeing the same failure rate.
- doikor 5y ago
  As I understand it another driver in the same rack doing work is enough to effect the performance of the other drivers in the rack. This is why you use fancy expensive "enterprise grade" drives as they can cope better with it. https://www.dtc.umn.edu/publications/reports/2005_08.pdf https://www.dtc.umn.edu/publications/reports/2005_08.pdf > In the presence of an external vibration caused by adjacent disk drive seek operations the bandwidth performance of a consumer-grade disk drive “feeling” these vibrations will decrease about 10%-15% when reading data and about 25%-40% when writing data Don't really know if this is enough to actually cause damage if the disk does not have the hardware to detect this vibration.
  - fuckyouriotshit 5y ago
    There's also this great example of Brendan Gregg screaming at hard disks to demonstrate exactly that sort of latency spike: https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4 I don't know if the latency spike is caused by sensors detecting the extra vibrations and delaying a read or seek operation or if its just vibrations causing minor read-head errors which either require a 2nd pass (that isn't reported through to the OS via SMART) or some sort of extra processing to pull the correct signal out of the raised noisefloor. Edit: person shouting at the disks is Brendan Gregg, not Bryan Cantrill.
- loeg 5y ago
  Apparently, yeah. Here's the classic video on the topic: https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4
neurostimulant 5y ago
Is there any way to tap this hdd sensors data on linux? I remember there were some apps on windows that read these hdd sensors data and use them as accelerometer / gyro, which was pretty neat when run on a laptop (this was when iBeer and virtual lighter apps were still a hot thing).

by doikor 5y ago

daneel_w 5y ago

Do drives in this type of stationary assembly (i.e. a server rack or a stationary PC) ever trigger their vibration protection? Barring of course during a bit of bumping in the server rack. I mean, these drives are not sitting in laptops. I have a hard time thinking the lack of this feature bears any weight on the huge failure rates Backblaze and discrete customers saw, though I'd accept the argument if there was a 2.5" laptop model of that drive seeing the same failure rate.

doikor 5y ago
As I understand it another driver in the same rack doing work is enough to effect the performance of the other drivers in the rack. This is why you use fancy expensive "enterprise grade" drives as they can cope better with it. https://www.dtc.umn.edu/publications/reports/2005_08.pdf https://www.dtc.umn.edu/publications/reports/2005_08.pdf > In the presence of an external vibration caused by adjacent disk drive seek operations the bandwidth performance of a consumer-grade disk drive “feeling” these vibrations will decrease about 10%-15% when reading data and about 25%-40% when writing data Don't really know if this is enough to actually cause damage if the disk does not have the hardware to detect this vibration.
- fuckyouriotshit 5y ago
  There's also this great example of Brendan Gregg screaming at hard disks to demonstrate exactly that sort of latency spike: https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4 I don't know if the latency spike is caused by sensors detecting the extra vibrations and delaying a read or seek operation or if its just vibrations causing minor read-head errors which either require a 2nd pass (that isn't reported through to the OS via SMART) or some sort of extra processing to pull the correct signal out of the raised noisefloor. Edit: person shouting at the disks is Brendan Gregg, not Bryan Cantrill.
loeg 5y ago
Apparently, yeah. Here's the classic video on the topic: https://www.youtube.com/watch?v=tDacjrSCeq4 https://www.youtube.com/watch?v=tDacjrSCeq4

neurostimulant 5y ago

Is there any way to tap this hdd sensors data on linux? I remember there were some apps on windows that read these hdd sensors data and use them as accelerometer / gyro, which was pretty neat when run on a laptop (this was when iBeer and virtual lighter apps were still a hot thing).