$ mongod --port 27017 --dbpath /srv/mongodb/db0 --replSet rs0
2014-08-28T15:04:04.492+0100 [initandlisten] MongoDB starting : pid=1305 port=27017 dbpath=/srv/mongodb/db0 64-bit host=ubuntu
2014-08-28T15:04:04.493+0100 [initandlisten] db version v2.6.4
2014-08-28T15:04:04.493+0100 [initandlisten] git version: 3a830be0eb92d772aa855ebb711ac91d658ee910
2014-08-28T15:04:04.493+0100 [initandlisten] build info: Linux build7.nj1.10gen.cc 2.6.32-431.3.1.el6.x86_64 #1 SMP Fri Jan 3 21:39:27 UTC 2014 x86_64 BOOST_LIB_VERSION=1_49
2014-08-28T15:04:04.494+0100 [initandlisten] allocator: tcmalloc
2014-08-28T15:04:04.494+0100 [initandlisten] options: { net: { port: 27017 }, replication: { replSet: "rs0" }, storage: { dbPath: "/srv/mongodb/db0" } }
2014-08-28T15:04:04.494+0100 [initandlisten] exception in initAndListen: 10309 Unable to create/open lock file: /srv/mongodb/db0/mongod.lock errno:13 Permission denied Is a mongod instance already running?, terminating
2014-08-28T15:04:04.495+0100 [initandlisten] dbexit:
2014-08-28T15:04:04.495+0100 [initandlisten] shutdown: going to close listening sockets...
2014-08-28T15:04:04.495+0100 [initandlisten] shutdown: going to flush diaglog...
2014-08-28T15:04:04.496+0100 [initandlisten] shutdown: going to close sockets...
2014-08-28T15:04:04.496+0100 [initandlisten] shutdown: waiting for fs preallocator...
2014-08-28T15:04:04.496+0100 [initandlisten] shutdown: lock for final commit...
2014-08-28T15:04:04.496+0100 [initandlisten] shutdown: final commit...
2014-08-28T15:04:04.497+0100 [initandlisten] shutdown: closing all files...
2014-08-28T15:04:04.497+0100 [initandlisten] closeAllFiles() finished
2014-08-28T15:04:04.497+0100 [initandlisten] shutdown: removing fs lock...
2014-08-28T15:04:04.497+0100 [initandlisten] couldn't remove fs lock errno:9 Bad file descriptor
2014-08-28T15:04:04.497+0100 [initandlisten] dbexit: really exiting now