Parity is very simple, and it is basically the same concept wherever it is used and however it is implemented. Understanding how Unraid implements parity makes everything about how Unraid works, and how to work with Unraid, more understandable. If you're interested, follow this link

https://docs.unraid.net/unraid-os/getting-started/what-is-unraid/ and expand the "How Parity Works" section

12 hours ago, trurl said:

But it doesn't really matter if you repair the unmountable (but not disabled) disk before rebuilding, or rebuild the repaired emulated disk before repairing the unmountable disk. They are independent.

Then we're back to the problem with the dirty log on 1NFWTG. Is there any other way to try and fix the log since mounting the disk when starting the array in normal mode doesn't help?

Since the disk doesn't mount you need to fix the log, that's typically OK.

2 hours ago, JorgeB said:

Since the disk doesn't mount you need to fix the log, that's typically OK.

Thanks, the rebuild seems to have worked as expected (I didn't find a "lost+found" folder on the disk at least).

Again, thanks for all the help. I'm not sure which reply to mark as the answer though so I'll mark the first one from trurl.