So, judging from the file size drop in my nightly backups, Mint dropped all of my data at some point on the 20th or pre-3am 21st July. At this point it also stopped logging new data.
The trick to get it working again was to use the ?moved command. I’ve no idea what that actually does, but it worked.
I can’t identify anything that might have happened with the server (it’s a self-managed VPS) which might have confused Mint at that time. Another Mint install on the same box was unaffected by whatever it was.
I’ve updated Mint to 2.18 and latest pepper, although it was only mildly out of date.
I’ve restored my data from the backup on the 21st, but I’ve obviously not been logging stats for the last 10 days. In truth, it doesn’t matter for this site, but I’d like to understand the problem to prevent it happening to something important.
Shaun - what does ?moved actually do? Any ideas what would cause Mint to stop logging and drop all historical data?