Neo4j and big log files
These files are created whenever the logical logs are rotated.
You can configure rules for them in the server properties file.
See details here: http://docs.neo4j.org/chunked/stable/configuration-logical-logs.html
You can safely remove them (but only the *.v*) if your database is shutdown and in a clean state. Don't remove them while the db is running because they could be needed in case of recovery on a crash.