Hi,

After replacing the old parity disk (3TB) with a new one (4TB, precleared) and a data drive with smart issues replaced with the old parity disk following the official guide from the wiki (fantastic guide, by the way), I performed a parity check and 244188000 errors were detected and corrected (yes, 244 millions!). The parity status is Valid.

 

Other than that error, the server is working great, no other issue anywhere. I also replaced some SATA cables with better ones as recommended by @johnnie.black on another thread I opened when I begun having array writing issues, so everything is up and running as expected.

 

Could it be maybe some "leftover issues" from the old damaged drive? Should I panic?

So many errors suggest parity wasn't valid at some point during what you did, as long as future parity checks return 0 errors you should be fine.

Thank you Johnnie. I forgot to mention that I followed this guide step by step and saw no error during the process: https://wiki.unraid.net/The_parity_swap_procedure

But I suspect that the old damaged disk I replaced contained maybe those errors and so they were "transmitted" to the new replacement one.

Anyway, I'll follow your advice and will do another parity check this evening and check if it returns 0.

Thank you again

There have been some reports of sync errors being detected after doing the parity swap procedure once the parity check starts checking the capacity beyond the old parity size, unfortunately was never able to reproduce it, but it's possible that a bug exists but only it only happens in some specific cases, though it can only be that if the sync errors started late in the check.