[smartmontools-support] Smartctl error prevents me from retrieving SMART data for a drive

[Christian Franke]

asorewinner wrote:
> I recently got an error when trying to use GSmartControl to read SMART 
> data on one of my external hard drives.
>
> The drive shows up as an Unknown model, even though GSmartControl had 
> previously worked on it. When I right-click and go to View Details, it 
> shows "Cannot retrieve SMART data - Device open failed, or device did 
> not return an IDENTIFY DEVICE structure."
>
> Running "sudo smartctl -x /dev/sdx" where sdx was the drive in 
> question, I got "Read Device Identity failed: scsi error unsupported 
> field in scsi command. A mandatory SMART command failed: exiting. To 
> continue, add one or more '-T permissive' options."

The above is a typical symptom for USB drives under Linux if UAS 
transfer mode is enabled. For further info and links to related tickets 
see https://www.smartmontools.org/wiki/USB

If it may be a different issue, please be more specific: platform, 
smartmontools version, drive model, controller type, ...?

Thanks,
Christian