[smartmontools-support] problem with scterc on a mac

[Christian Franke]

Dennis Couzin wrote:
> Dear Christian,
> I don't understand why you asked, but I confirmed that  "smartctl -l scttemp" running on Darwin does print the temperature table:
>
> 	evas-system:~ evaheldmann$ smartctl -l scttemp /dev/disk4
> 	smartctl 7.0 2018-12-30 r4883 [Darwin 16.7.0 x86_64] (local build)
> ...
> 	Current Temperature:                    28 Celsius
> 	...
> 	  13    2020-02-08 13:47    28  *********

I asked because -l scttemp uses the same command (SMART_WRITE_LOG) as -l 
scterc (get), but with different parameters.


> I also don't understand the 2008 ATA8-ACS final draft's statement: "a device shall not change these settings while processing a hardware reset or a software reset".  What are hardware or software resets and when do they occur?

These are device resets issued via specific (hardware) signal sequences 
on the SATA link or specific SATA (software) commands. Those resets 
typically occur during boot and may occur later if the device driver 
detects problems, e.g. SATA CRC errors.


> Powering off and on certainly does change the ERC settings on some drives (e.g., my WD Red Pro, manufactured 2016) but not on other drives (e.g., my Toshiba N300, manufactured 2019).

Then the WD Red Pro honors the ATA standard but the Toshiba N300 does 
not. A power cycle shall reset the ERC settings to factory defaults.

Regards,
Christian