Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1637318

Re: Race to power off harming SATA SSDs

Show all headers | View raw

Hi,

On 08-05-17 11:06, Ricard Wanderlof wrote:
> 
> On Mon, 8 May 2017, David Woodhouse wrote:
> 
>>> On Mon, 8 May 2017, David Woodhouse wrote:
>>>> Our empirical testing trumps your "can never happen" theory :)
>>>
>>> I'm sure it does. But what is the explanation then? Has anyone analyzed
>>> what is going on using an oscilloscope to verify relationship between
>>> erase command and supply voltage drop?
>>
>> Not that I'm aware of. Once we have reached the "it does happen and we
>> have to cope" there was not a lot of point in working out *why* it
>> happened.
>>
>> In fact, the only examples I *personally* remember were on NOR flash,
>> which takes longer to erase. So it's vaguely possible that it doesn't
>> happen on NAND. But really, it's not something we should be depending
>> on and the software mechanisms have to remain in place.
> 
> My point is really that say that the problem is in fact not that the erase
> is cut short due to the power fail, but that the software issues a second
> command before the first erase command has completed, for instance, or
> some other situation. Then we'd have a concrete situation which we can
> resolve (i.e., fix the bug), rather than assuming that it's the hardware's
> fault and implement various software workarounds.

You're forgetting that the SSD itself (this thread is about SSDs) also has
a major software component which is doing housekeeping all the time, so even
if the main CPU gets reset the SSD's controller may still happily be erasing
blocks.

Regards,

Hans

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 00:00 +0200
  Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 09:30 +0200
    Re: Race to power off harming SATA SSDs Ricard Wanderlof <ricard.wanderlof@axis.com> - 2017-05-08 09:40 +0200
      Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 10:20 +0200
        Re: Race to power off harming SATA SSDs Ricard Wanderlof <ricard.wanderlof@axis.com> - 2017-05-08 10:40 +0200
          Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 11:00 +0200
            Re: Race to power off harming SATA SSDs Ricard Wanderlof <ricard.wanderlof@axis.com> - 2017-05-08 11:10 +0200
              Re: Race to power off harming SATA SSDs Hans de Goede <hdegoede@redhat.com> - 2017-05-08 11:10 +0200
                Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 12:20 +0200
                Re: Race to power off harming SATA SSDs Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-05-08 14:00 +0200
                Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 17:50 +0200
                Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 23:40 +0200
                Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 18:50 +0200
                Re: Race to power off harming SATA SSDs Tejun Heo <tj@kernel.org> - 2017-05-08 19:50 +0200
                Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 21:00 +0200
                Re: Race to power off harming SATA SSDs Tejun Heo <tj@kernel.org> - 2017-05-08 21:10 +0200
                RE: Race to power off harming SATA SSDs Atlant Schmidt <aschmidt@dekaresearch.com> - 2017-05-08 20:50 +0200
              Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 12:20 +0200
    Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 11:30 +0200
      Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 11:40 +0200
        Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 13:00 +0200
          Re: Race to power off harming SATA SSDs Richard Weinberger <richard.weinberger@gmail.com> - 2017-05-08 13:10 +0200
            Re: Race to power off harming SATA SSDs Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-05-08 14:00 +0200
            Re: Race to power off harming SATA SSDs Boris Brezillon <boris.brezillon@free-electrons.com> - 2017-05-08 14:00 +0200
              Re: Race to power off harming SATA SSDs Richard Weinberger <richard@nod.at> - 2017-05-08 14:20 +0200
          Re: Race to power off harming SATA SSDs David Woodhouse <dwmw2@infradead.org> - 2017-05-08 13:20 +0200
            Re: Race to power off harming SATA SSDs Pavel Machek <pavel@ucw.cz> - 2017-05-08 14:40 +0200
      Re: Race to power off harming SATA SSDs Richard Weinberger <richard.weinberger@gmail.com> - 2017-05-08 12:00 +0200

csiph-web