smartd and smartctl - SMART status command failure

Hi,

When I run smartctl it reported below error and same with smartd.

 START OF READ SMART DATA SECTION === 
SMART Status command failed Please
get assistance from http://smartmontools.sourceforge.net/
Register values returned from SMART Status command are:
 ERR=0x00, SC=0x00, LL=0x00, LM=0x00, LH=0x00, DEV=0x00, STS=0x00 SMART
Status not supported: Invalid ATA output register values SMART
overall-health self-assessment test result: PASSED
Warning: This result is based on an Attribute check.

Similarly smartd reported:
Device: /dev/sdc, type changed from 'scsi' to 'sat'
Device: /dev/sdc [SAT], opened
Device: /dev/sdc [SAT], HGST HUS726060ALN610, S/N:NAHYUEUX,
WWN:5-000cca-242dba5c9, FW:APGNT7J0, 6.00 TB
Device: /dev/sdc [SAT], not found in smartd database.
SMART Status command failed
Please get assistance from http://smartmontools.sourceforge.net/
Register values returned from SMART Status command are:
 ERR=0x00, SC=0x00, LL=0x00, LM=0x00, LH=0x00, DEV=0x00, STS=0x00
Device: /dev/sdc [SAT], not capable of SMART Health Status check Unable to
register ATA device /dev/sdc [SAT] at line 23 of file /etc/smartmontools
/smartd.conf

It appears "smartctl" though failed the SMART status command, it checked the
attribute threshold values and indicated "Disk is OK" but smartd doesn't do
the latter and bails out as soon as SMART status command failed? Is that
understanding correct?

My questions are:
1) What causes the above error and any solutions to overcome this and
monitor the drive?
2) Given the above error looks like "smartd" doesn't do any monitoring on
the device in this case, hence if we still want to monitor the device can we
modify it to check the attribute values similar to how smartctl does? Just
as an experiment?
3)How to update the drives in the database since smartctl complains the
drives are missing in its database.
4)How to inject SMART errors to simulate and test SMART errors are being
monitored and reported

Appreciate your help and Thanks in advance. The log files attached with this
mail are reported with debug and ioctl options.

Thanks & regards,
Naveen Karthick.C


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