Yes, you’ll see a downloaded line with the type GET_AUDIT if it was successful. If you see a download failed line with GET_AUDIT the audit failed for some reason. The error will mention the specific reason, like “file does not exist”.
I don’t believe there is a log for this, but satellites do communicate back the total number of audits and the number of successful ones. You can find these using the Storage node dashboard API (v0.19.0) .
I don’t think it is. During audit the satellite retrieves a stripe (a small bit of a piece) from all nodes hosting it. The satellite then tries to recreate the data using erasure codes and detects which pieces are corrupt. This is not a process you can do as a single node, it requires the stripes from the other nodes.