Burn in testing error message question

[katit]

I'm building new NAS (details in sig) based on Supermicro MB. I flashed SAS to IT v16, no errors. Everything looks OK. SMART data and so on. I follor instructions from sticky and when I run following I got error:

badblocks -ws /dev/da0

Testing with pattern 0xaa: set_o_direct: Inappropriate ioctl for device
done
Reading and comparing: done
Testing with pattern 0x55: done
Reading and comparing: done
Testing with pattern 0xff: done
Reading and comparing: 64.67% done, 15:12:00 elapsed. (0/0/0 errors)

Test is still going, but what is this error?
Testing with pattern 0xaa: set_o_direct: Inappropriate ioctl for device

 

[katit]

Seems like I found it:
https://forums.freenas.org/index.php?threads/badblocks-testing-inappropriate-ioctl-for-device.26015/

 

[HardChargin]

Seems like I found it:
https://forums.freenas.org/index.php?threads/badblocks-testing-inappropriate-ioctl-for-device.26015/

I went through the exact same concern and conclusion. I tried changing some flags, but it made no difference. Ultimately I would like to get a better understanding of the error myself.