SATA disk disappears

[Wojciech Puchar]

>> GEOM_MIRROR: Component ada2 (device home1) broken, skipping.
>> GEOM_MIRROR: Cannot add disk ada2 to home1 (error=22).
>> 
>> 
>> started gmirror rebuild and it now works at full speed.
>> 
>> GEOM_MIRROR: Device home1: rebuilding provider ada2.
>> 
>> 
>> What kind of hardware failure may it be? smartctl -a /dev/ada2 shows disk 
>> is fine.
>
> I had a new WD drive recently that had a write error.  Reallocated sector 
> count did not go up, but it quickly failed the SMART self-test, short or 
> long.  See smartctl(8) about the -t parameters.
>
this is WD "green" 3TB