Wow, this is bizarre, I have the exact same problem but what's even more amazing is that my 5 errors were at the same exact 5 sectors! I thought I would have found the bad drive while upgrading from Riserfs to xfs and upgrading my parity drive from a 4TB to a 5TB but now I have 5 sectors incorrect in a different location constantly. During my FS upgrade, I changed two drives at a time and did parity checks with the same errors each time. This is not a bad drive problem at all but some kind of error caused by the hardware or software.
Before:
Apr 4 18:28:39 unRAID kernel: md: correcting parity, sector=3519069768
Apr 4 18:28:39 unRAID kernel: md: correcting parity, sector=3519069776
Apr 4 18:28:39 unRAID kernel: md: correcting parity, sector=3519069784
Apr 4 18:28:39 unRAID kernel: md: correcting parity, sector=3519069792
Apr 4 18:28:39 unRAID kernel: md: correcting parity, sector=3519069800
Now:
Apr 7 07:57:11 unRAID kernel: md: correcting parity, sector=1177606472
Apr 7 07:57:11 unRAID kernel: md: correcting parity, sector=1177606480
Apr 7 07:57:11 unRAID kernel: md: correcting parity, sector=1177606488
Apr 7 07:57:11 unRAID kernel: md: correcting parity, sector=1177606496
Apr 7 07:57:11 unRAID kernel: md: correcting parity, sector=1177606504
I have done at least 10 parity check with the first set of bad sectors and about 5 with the second. I hope we can get to the bottom of this.