Smartctl issues in Cygwin with elevated terminal

Christian Franke
Tue Sep 13 17:23:48 GMT 2022

Hamish McIntyre-Bhatty wrote:
> I recently noticed that smartctl only works when the Cygwin Terminal 
> isn't run as administrator - the opposite way round to Linux where you 
> need superuser privileges to access the disk.
> With Administrator privileges on Windows 11, I get:
> "Read Device Identity Failure Input/Output error"

This likely happens because one of the tried pass-through I/O-controls 
returns an error code which does not mean "not implemented". This is a 
limitation or bug in the driver of the disk controller.

For further diagnostics, try for example. 'smartctl -r ioctl,2 -i /dev/sda'

> But it continues to work fine as a normal user.

When run without admin rights for a SATA device, smarctl may print:
"Warning: Limited functionality due to missing admin rights"
and then prints only limited device identify and SMART DATA information 

Other functionality requires admin rights and a working pass-through 
I/O-control - try 'smartctl -x /dev/sda'.

Please note that the above is not Cygwin specific as it applies to both 
(Cygwin and Mingw-w64) Windows builds of smartctl. Use this ML for 
related support requests:

> Does anyone know why? In my case, this actually matters because I'm 
> not sure how to elevate and/or drop privileges in Cygwin, as sudo 
> doesn't work due to it not being Unixy underneath.

To drop privileges, try 'cygdrop' tool from 'cygutils-extra' package.


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