My photo library was on the one drive with no mirror. The obvious folder to move it to, on the mirror, was a symlink straight back to the photos.
I replaced the example config on my Homepage dashboard and the page source still showed the examples. It survived a full container recreate, because it was never my config to begin with.
My ZimaBoard had been running an eight-month-old alpha since January, and the built-in updater said there was nothing newer. There was. Getting to it meant learning what 100% on the root filesystem actually means on this box.
A homelab migration filled the system disk and the storage layer lost track of a perfectly healthy array. Here is why I wiped and rebuilt from backup instead of recovering in place.