So - I was having problems whenever openHAB started up. Sometimes it would pause for two minutes, sometimes it would never start up; sometimes the delay in starting up caused strange errors (likely caused by rules running at a point when items were undefined). Couldn’t see the problem from logs, and the pause occurred at different times on each startup.
After digging around, I saw that my db4o database file in /var/lib/openhab/persistence/db4o had somehow grown to 15MB. I deleted it and restarted, and everything is now good. Given the persistence file usually grows by 2k each day, I’m not sure how it ever reached 15MB.
I mention this just in case anyone else ever experiences the same symptoms