how to measure microsd wear

[Warner Losh]

On Sun, Jan 22, 2017 at 4:55 AM, tech-lists <tech-lists at zyxst.net> wrote:
> On 22/01/2017 02:53, Rodney W. Grimes wrote:
>> In either case the manufactures of flash devices have made it very
>> clear that these things DO have a write cycle life time, and that
>> your going to see a failure eventually if you write enough data to
>> them.
>
> Hi,
>
> Is there a way one can see how many (or an average) number of write
> cycles the cluster or device has had? In order to get a handle on when
> it's likely to fail. Or to see what's been remapped and how many more it
> can remap? If not on freebsd then on any OS?
>
> Maybe something that tests # remappable and warns when there's nothing left?
>
> I mean it's all fair and well the manufacturers saying it will fail on
> average after so many writes, but that uncontextualised information is
> useless if one cannot establish how many writes have already happened.

There's no standard way to get this data. There's several ways to get
this data, but it's a terribly gerrymandered, poorly documented
landscape at best.

Warner