Hello,
Few WDC 3.5 inch SATA III internal hdd’s (purchase date last 24 months) are populated to NAS device. The NAS device offers scheduling of SMART tests, easy (simple) or complete (extensive). If such tests scheduled they are carried out during the device normal operation. It means during the tests files can be open or locked by system (apps). Are these tests destructive for data stored on the drives?