I've been running a backup job for a few days now, backing up to AWS S3. I'm backing up all files on my Mac HD, including all hidden files. When I click on the backup job, each one shows that it failed, indicating that about 11 to 14 files did not copy. I assume this is because the file is busy (open) in some background process. But, it would be nice to know which file is failing. How can I find that out? Is there a backup log somewhere?