[smartmontools-support] Understanding 'not capable of SMART self-check' and 'failed to read SMART Attribute Data' from smartd?

[Christian Franke]

Dachshund Digital wrote:
> Understanding 'not capable of SMART self-check' and 'failed to read 
> SMART Attribute Data' from smartd?
>
> I can execute the -H check which reports PASSED for the drive in 
> question.  I can execute the -P show variant of the smartctl command 
> sequence.  I can execute the (detail) information variant of the 
> smartctl command sequence.  No errors or alerts presented by any of 
> the these commands, so I don't understand what smartd is reporting, 
> when the results from smartctl show no issues, apparently?  I am new 
> to smartmontools... so am I missing something (obvious) here?
>
> ...
>
> From smartd...
>
> Nov 16 00:19:50 pi4modelb1.[redacted] smartd[5105]: Warning via to 
> [redacted]: successful
> Nov 16 00:19:52 pi4modelb1.[redacted] smartd[5105]: Device: /dev/sda 
> [SAT], failed to read SMART Attribute Data
> Nov 16 00:19:52 pi4modelb1.[redacted] smartd[5105]: Sending warning 
> via to [redacted] ...
> Nov 16 00:19:52 pi4modelb1.[redacted] smartd[5105]: Warning via to 
> [redacted]: successful
> Nov 16 00:20:00 pi4modelb1.[redacted] smartd[5105]: Device: /dev/sdb 
> [SAT], not capable of SMART self-check
> Nov 16 00:20:00 pi4modelb1.[redacted] smartd[5105]: Sending warning 
> via to [redacted] ...
> Nov 16 00:20:00 pi4modelb1.[redacted] smartd[5105]: Warning via to 
> [redacted]: successful
> Nov 16 00:20:02 pi4modelb1.[redacted] smartd[5105]: Device: /dev/sdb 
> [SAT], failed to read SMART Attribute Data
> Nov 16 00:20:02 pi4modelb1.[redacted] smartd[5105]: Sending warning 
> via to [redacted] ...
> Nov 16 00:20:02 pi4modelb1.[redacted] smartd[5105]: Warning via to 
> [redacted]: successful

This happens when the initial device registration was successful but 
some I/O-problem occurred later.
Try '/usr/sbin/smartd -q onecheck' (see man page for details).


>
> From smartd.conf...  Is my understanding that per the documentation, 
> ANY THING after the DEVICESAN line is IGNORED, this per the 
> documentation in the default smartd.conf file.

That is correct.


> /dev/sda -m [redacted] -M test
> /dev/sdb -m [redacted] -M test

These lines do not specify -n standby. I/O-errors like above may occur 
if a device is in standby mode (depends on drive firmware and device 
driver).


>
> DEVICESCAN -d removable -n standby -m root -M exec 
> /usr/share/smartmontools/smartd-runner

This -n standby has no effect for /dev/sda and /dev/sdb.


>
> /dev/sda -l error \
> ...
> /dev/sda -l error \
> ...
>

These lines are ignored.

Regards,
Christian