Data Life Guard Diagnostics
Western Digital provide the Data Life Guard Diagnostics software for both Windows and DOS boot. This software can provide a number of hard drive tests - including a full surface scan, known as the Extended test - and also reports back drive SMART health information.
However, it appears that DLG may sometimes only report any failing SMART information once the warranty failure threshold has been reached. Or it may not report some SMART attributes correctly ay all.
This means that using the DLG tool and getting a perfect, clean bill of health from the tool may not provide an accurate assessment of the drive's health.
An example scenario is shown below.
This proves that WD Data Lifeguard Diagnostics cannot be relied upon when it reports that the drive is perfectly healthy. Engineers should be aware of this, and should use other utilities that read the real SMART information directly, such as the SMART Gather Tool.