I'll try to get the primary upgraded over the weekend when we can afford a restart.
In the meantime I have a single test showing that a shutdown, snapshot, restart produces a backup that passes the vacuum analyze test. I'm going to run a full vacuum today.
The subject says 9.2.3. Are you sure you're running 9.2.4 on all the
servers? There was a fix to a bug related to starting a standby server from a filesystem snapshot. I don't think it was quite the case you have, but pretty close.
So this is delightfully embarrassing I just went back to double check and
- primary box is 9.2.3 - standby is 9.2.4 - testing is 9.2.4
I guess that alone could possibly explain it?
Hmm, no, it should still work. There haven't been any changes in the WAL format. I do recommend upgrading the primary, of course, but I don't really see how that would explain what you're seeing.