4 ms·

taking all the data with it Man, I thought the failure mode of SSDs was (mostly) "can't write anymore, but can at least read, so backup NOW and get a new one".

taking all the data with it Man, I thought the failure mode of SSDs was (mostly) "can't write anymore, but can at least read, so backup NOW and get a new one". Or am I overanalyzing parent's statement, and taking it too literally?

gvb 5y ago
I don't have a lot of experience with SSDs, but my impression is that their failure mode tends to be abrupt complete failure. The "soft" failure mode is based on the assumption that the flash chip wear-out is the failure mode and thus the worn out pages will be (slowly) accumulating and being (gracefully) replaced with non-worn-out pages. If that happens, the failure would indeed be gradual and result in the SSD going into a read-only mode. My (limited) experience is that is not the dominant failure mode. It would be really useful if BackBlaze could weigh in on their failure mode experiences. ---- It is like LED lights where the manufacturer advertises essentially infinite LED life and they are not lying; the LEDs last a very long time. The problem is, the dominant failure mode is the electronics that power the LEDs and have a MUCH shorter life that the LEDs themselves. <cough> cheap caps </cough>
rasz 5y ago
This is marketing and wishful thinking, most times when SSD dies critical system nand gets corrupted. Intel was boasting about safe read only failover, and then when it turned out their shit drives just die like the rest they invented "we shutdown read access to protect our clients" :---) https://techreport.com/review/26523/the-ssd-endurance-experiment-casualties-on-the-way-to-a-petabyte/ https://techreport.com/review/26523/the-ssd-endurance-experi... "After a reboot, the SSD disappeared completely from the Intel software. It was still detected by the storage driver, but only as an inaccessible, 0GB SATA device. According to Intel, this end-of-life behavior generally matches what’s supposed to happen. The write errors suggest the 335 Series had entered read-only mode. When the power is cycled in this state, a sort of self-destruct mechanism is triggered, rendering the drive unresponsive. "

gvb 5y ago

I don't have a lot of experience with SSDs, but my impression is that their failure mode tends to be abrupt complete failure. The "soft" failure mode is based on the assumption that the flash chip wear-out is the failure mode and thus the worn out pages will be (slowly) accumulating and being (gracefully) replaced with non-worn-out pages. If that happens, the failure would indeed be gradual and result in the SSD going into a read-only mode. My (limited) experience is that is not the dominant failure mode. It would be really useful if BackBlaze could weigh in on their failure mode experiences. ---- It is like LED lights where the manufacturer advertises essentially infinite LED life and they are not lying; the LEDs last a very long time. The problem is, the dominant failure mode is the electronics that power the LEDs and have a MUCH shorter life that the LEDs themselves. <cough> cheap caps </cough>

rasz 5y ago

This is marketing and wishful thinking, most times when SSD dies critical system nand gets corrupted. Intel was boasting about safe read only failover, and then when it turned out their shit drives just die like the rest they invented "we shutdown read access to protect our clients" :---) https://techreport.com/review/26523/the-ssd-endurance-experiment-casualties-on-the-way-to-a-petabyte/ https://techreport.com/review/26523/the-ssd-endurance-experi... "After a reboot, the SSD disappeared completely from the Intel software. It was still detected by the storage driver, but only as an inaccessible, 0GB SATA device. According to Intel, this end-of-life behavior generally matches what’s supposed to happen. The write errors suggest the 335 Series had entered read-only mode. When the power is cycled in this state, a sort of self-destruct mechanism is triggered, rendering the drive unresponsive. "