Client is using directoryPerDB and dbPath=/data is a mount point. It looks like mongoldb is treating the lost+found directory as a database and trying to access the ns file, which obviously doesn't exist. We should make sure we don't try to access this directory.
2016-10-17T05:53:11.077-0700 E NETWORK [conn3] Uncaught std::exception: boost::filesystem::status: Permission denied: "/data/lost+found/lost+found.ns", terminating
2016-10-17T05:53:11.077-0700 I - [conn3] Assertion failure c src/mongo/db/client.cpp 157