I just bought unraid a couple of weeks ago and had the monthly parity check run a few days ago. It discovered 90 errors but all my disks (7) are reporting 0 errors.

What exactly should I do with this information? I've had 1 unclean shutdown in recent weeks so my understand is that this could've caused sync errors. Should I just run another parity check with "Write corrections to parity" enabled and be unconcerned about the 90 errors?

Correct parity then another noncorrecting to confirm.

These 90 errors are most likely the result of unwritten buffers due to your unclean shutdown.

UNRAID first writes the data, then the parity. So, if interrupted, it is a good chance, that the data is already correct on disk, just the parity is out of sync.

To check (and fix) this (as @trurl already said):

• start a parity check with "write corrections"

• wait until it is finished (should show the 90 errors again)

• start another parity check without corrections

The result of the latter should be 0, this means the data is correct and the parity is back in sync again.

Avoid unclean shutdowns, they will always kill the parity. If you produce them often, consider to tick the "write corrections" mark in the settings to allow direct corrections in the pass that is always fired up after a restart following an unclean shutdown. This CAN cover real errors, but this is very rare. (use at your own risk)