The BACKUP_END, BACKUP_STATS, RESTORE_END, and RESTORE_STATS log messages are convenient for extracting a useful summary of backup and restore operations. Please implement something similar for the copy, prune, and check commands.
What specific information are you looking for? The web GUI parses a lot of log messages which appear to be enough for it to work properly.
The short answer is that I’m not sure, because I’m not familiar with what information is available and relevant. One concern is that if I log all messages with a particular keyword, situations will occur where this produces excessively many and/or lengthy log entries. It’s similar to the problem of having to figure out what to filter on to reduce the size of the “Send email after completion” reports.
For copy, it looks like logging SNAPSHOT_COPY messages would be safe and relevant to log, yes?
For prune, I don’t yet have examples of duplicacy output when snapshots are deleted.
End/stats messages for check would be the most useful. All messages are tagged SNAPSHOT_CHECK, and I don’t have examples of duplicacy output when check fails.
Here’s an example: for copy, logging all SNAPSHOT_COPY messages normally produces a useful summary. But when copying a large storage to a new storage, this can log thousands of “SNAPSHOT_COPY Copied snapshot X at revision Y messages”.