not OP, but I would start with filling disk space up to 100%, or creating zillions of empty files. In case of distributed filesystems - maybe removing one node

not OP, but I would start with filling disk space up to 100%, or creating zillions of empty files. In case of distributed filesystems - maybe removing one node (under heavy load preferably), or "cloning" nodes so they had same UUIDs (preferably nodes storing some data on them - to see if the data will be de-duplicated somehow). Or just a disk with unreliable USB connection?