I was syncing a new parity drive and not long into this operation one of my oldest drives threw 30 read errors, and another 82 the day after. However the sync completed successfully. I have ran an extended self-test on the drive and it completed without error too. Wondering whether this drive is failing, or perhaps this is because the sync forced a read of a long forgotten part of the disk? (read somewhere this can be a cause of this). I have not run a full parity check for about two months, since changing my schedule to quarterly so perhaps that would have caused this too.

 

I have a new 18TB drive ready but I'd prefer to keep this disk in the array.

 

I've attached the latest SMART report. 

 

Thanks.

tower-smart-20230611-1417.zip

Those errors are not a good sign, but if the SMART test passed disk is OK for now, keep monitoring, especially attributes 1 and 200, if they keep climbing and/or there are more read errors consider replacing the disk. 

OK, thanks, I suspect it's on the way out. I'm thinking perhaps because I've recently started spinning down drives this has put added wear on them but as it has been powered on for over five years it's to be expected.