[smartmontools-support] selt-tests hours record inferior to current power in hours

[Carlos E. R.]

On 2022-05-02 13:43, Corentin Labbe wrote:
> Hello
> 
> When doing a self test, I have multiple drive which record it with a lifetime different than current power on hours:
> Example 1:
>    9 Power_On_Hours          0x0032   089   089   000    Old_age   Always       -       52717
> Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
> # 1  Short offline       Completed without error       00%      9937         -
> # 2  Short offline       Completed without error       00%      9821         -
> # 3  Extended offline    Completed without error       00%      9818         -
> # 4  Extended offline    Completed without error       00%      9776         -
> # 5  Extended offline    Completed without error       00%      7284         -
> # 6  Extended offline    Completed without error       00%      7284         -
> # 7  Short offline       Completed without error       00%     17463         -
> # 8  Extended offline    Completed without error       00%     16958         -
> # 9  Extended offline    Completed without error       00%     15021         -
> #10  Extended offline    Completed without error       00%     14404         -
> #11  Extended offline    Completed without error       00%     14386         -
> 
> This driver just got a self test today
> As can be seen, the last is at 9937 hours but current Power_On_Hours is 52717.

The first is 9937, not the last :-)

> 
> Example 2:
> I got another driver with the same problem:
>    9 Power_On_Hours          0x0032   007   007   000    Old_age   Always       -       68178
> Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
> # 1  Short offline       Completed without error       00%      2642         -
> # 2  Short offline       Completed without error       00%      2642         -
> # 3  Extended offline    Interrupted (host reset)      90%      1346         -
> # 4  Extended offline    Interrupted (host reset)      80%      1298         -
> # 5  Extended offline    Interrupted (host reset)      10%       483         -
> # 6  Extended offline    Completed without error       00%       467         -
> # 7  Extended offline    Interrupted (host reset)      50%     61490         -
> # 8  Extended offline    Completed without error       00%     60302         -
> # 9  Short offline       Completed without error       00%     60299         -
> #10  Extended offline    Completed without error       00%     60028         -
> #11  Extended offline    Completed without error       00%     58615         -
> #12  Short offline       Completed without error       00%     58568         -
> #13  Extended offline    Completed without error       00%     52790         -
> #14  Extended offline    Completed without error       00%     50530         -
> #15  Extended offline    Completed: read failure       90%     50290         105986680
> #16  Extended offline    Completed without error       00%     50057         -
> #17  Short offline       Completed without error       00%     50054         -
> 
> In example 2, the difference is exactly 65536, but example 1 is 42780.
> 
> Does this is normal ?

Yep. Unsigned integer wrap (16 bit).


-- 
Cheers / Saludos,

		Carlos E. R.
		(from 15.3 x86_64 at Telcontar)
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