配置文件内容：

cat /etc/mongodb.conf

storage:
    dbPath: "/data/databases/mongodb"
    directoryPerDB: true
    journal:
        enabled: true
    wiredTiger:
        engineConfig:
            cacheSizeGB: 100
systemLog:
    destination: file
    path: "/data/databases/mongodb/mongodb.log"
    logRotate: rename
    logAppend: true
    timeStampFormat: iso8601-local
operationProfiling:
   slowOpThresholdMs: 200
   mode: slowOp
replication:
    oplogSizeMB: 51200
    replSetName: "rschunqiu"
processManagement:
    fork: true
net:
    bindIp: 0.0.0.0
    port: 27017
security:
    keyFile: "/data/databases/mongodb/mongodb-keyfile"
    authorization: "enabled"

启动mongodb：

/usr/local/mongodb/bin/mongod --config /etc/mongodb.conf