Relatively new WD Red Pro yielding ATA status: 41 (DRDY ERR), error: 40 (UNC ) on FreeBSD 12.2

Solution 1:

UNC means UNCorrectable errors, which are often due to medium error (ie: a physical sector gone bad). However, you SMART log shows that the error happened at LBA 0x0. While theoretically possible, it seems very strange to me that you precisely hit a read error at that address. This seems confirmed by the reported SMART pending sectors (0), but I saw many disks not updating that field correctly.

Can you read LBA 0 at all? Please report what happens when executing the following command:

dd if=<your_disk> of=/dev/null bs=512 count=1 iflag=direct

If you can successfully read LBA, it is probable that you have a cabling issue or that the electronic of your HDD is failing/unstable.

Solution 2:

Thank you very much for your replies. Based on what you said I decided to RMA the drive to Western Digital. The drive has already been replaced.