storage:
    queryableBackupMode: true

mongod -f config.yml --replSet s0

rs.initiate()

2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] MongoDB starting : pid=4818 port=27017 dbpath=/data/db 64-bit host=ren-desktop
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] db version v3.3.5-29-g821c605
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] git version: 821c605f9aff83958e1c584a82d691b725e9adb6
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] allocator: tcmalloc
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] modules: none
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] build environment:
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten]     distarch: x86_64
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten]     target_arch: x86_64
2016-04-26T16:47:22.939-0400 I CONTROL  [initandlisten] options: { config: "config.yml", replication: { replSet: "s0" }, storage: { queryableBackupMode: true } }
2016-04-26T16:47:22.957-0400 I -        [initandlisten] Detected data files in /data/db created by the 'wiredTiger' storage engine, so setting the active storage engine to 'wiredTiger'.
2016-04-26T16:47:22.957-0400 I STORAGE  [initandlisten] wiredtiger_open config: create,cache_size=15538M,session_max=20000,eviction=(threads_max=4),config_base=false,statistics=(fast),readonly=true,
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] 
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] ** NOTE: This is a development version (3.3.5-29-g821c605) of MongoDB.
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] **       Not recommended for production.
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] 
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] 
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] **        We suggest setting it to 'never'
2016-04-26T16:47:23.009-0400 I CONTROL  [initandlisten] 
2016-04-26T16:47:23.015-0400 I NETWORK  [initandlisten] waiting for connections on port 27017
2016-04-26T16:47:23.015-0400 I NETWORK  [HostnameCanonicalizationWorker] Starting hostname canonicalization worker
2016-04-26T16:47:32.008-0400 I NETWORK  [initandlisten] connection accepted from 127.0.0.1:49855 #1 (1 connection now open)
2016-04-26T16:47:37.655-0400 I COMMAND  [conn1] initiate : no configuration specified. Using a default configuration for the set
2016-04-26T16:47:37.655-0400 I COMMAND  [conn1] created this configuration for initiation : { _id: "s0", version: 1, members: [ { _id: 0, host: "ren-desktop:27017" } ] }
2016-04-26T16:47:37.655-0400 I REPL     [conn1] replSetInitiate admin command received from client