 <p>Are you running the whole import in one big transaction? Try to split it up in transactions of, say, 10k nodes. You should still however not run into "too many open files". If you do an "lsof" (terminal command) at that time, can you see which files are open?</p> <p>Data that is committed stays persisted in a neo4j database. I think that the import fails with this error and nothing stays imported since the whole import runs in one big transaction.</p>