[smartmontools-support] problem with scterc on a mac

[Dennis Couzin]

Christian Franke, Sun 02/02/2020 16:27, replied to my post of Wed 29/01/2020 22:33:

>The API supports the SMART_WRITE_LOG command, so it should  
>work to set ERC. But you cannot check the result because get 
>ERC does not work due to API restrictions.
>
>This may not work because ERC settings are usually not  
>persistent across power cycles and device resets.

Replying to Christian:

Thanks for warning about non-persistent ERC settings.  Sure enough, for my WD Red Pro drive (4TB SATA), Linux smartctl could set arbitrary scterc,x,y, but on restart the drive reverted to its default settings (70,70).  However, my Toshiba N300 drive (6TB SATA) does take persistent ERC settings.  That is, they persist when set in Linux.  

The Darwin smartctl seems to do something very bad on the Toshiba N300 drive.  It pretends to make new ERC settings, but it actually kills the ERC settings.  Restarting the drive with Linux, I found neither the new ERC settings from the Darwin smartctl nor the previous ERC settings from the Linux smartctl.  Instead there was reversion to this drive's default settings (0,0).  If my experiment was correct, then "smartctl -l scterc,x,y" in Darwin is worse than ineffective; it is dangerous.

Dennis