openssl rand -base64 741 > mongo_key

chmod 700 mongo_key

onwer chown mongodb:nogroup mongo_key

master = true
keyFile = /path/to/mongo_key

slave = true
source = <ip of master>
only = bookstore
keyFile = /usr/local/bookstore/mongo_key

use admin
db.runCommand( { resync: 1 } )

> use admin
switched to db admin
> db.addUser("root","zhuima")
WARNING: The 'addUser' shell helper is DEPRECATED. Please use 'createUser' instead
Successfully added user: { "user" : "root", "roles" : [ "root" ] }

> use local
switched to db local
> db.addUser("repl","zhuima")
WARNING: The 'addUser' shell helper is DEPRECATED. Please use 'createUser' instead
Successfully added user: { "user" : "repl", "roles" : [ "dbOwner" ] }

[root@redis ~]# sed -e '/^$/d;/^#/d' /etc/mongodb.conf 
bind_ip = 192.168.58.30
port = 27017
fork = true
pidfilepath = /var/run/mongodb/mongodb.pid
logpath = /var/log/mongodb/mongodb.log
dbpath =/mydata/data
journal = true
auth = true# 开启认证模式
master = true          # 指定该mongodb为master模式

[root@localhost ~]$ sed -e '/^$/d;/^#/d' /etc/mongodb.conf 
bind_ip = 192.168.58.10
port = 27017
fork = true
pidfilepath = /var/run/mongodb/mongodb.pid
logpath = /var/log/mongodb/mongodb.log
dbpath = /mydata/data
journal = true
auth = true  # 开启认证模式
slave = true  # 指定该mongodb为slave模式
source = 192.168.58.30:27017  # 指定master服务器

> db.printReplicationInfo()
this is a slave, printing slave replication info.
source:  192.168.58.30:27017
 syncedTo: Fri Jul 18 2014 10:22:31 GMT+0200 (CEST)
 = 22 secs ago (0.01hrs)  # 这个是指延迟时长