MongDB 启动警告 ”WARNING: soft rlimits too low.“问题解决一例

MongoDB 3.4启动的时候有如下告警:
# mongo
MongoDB shell version v3.4.13
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.13
Server has startup warnings: 
2018-02-27T15:03:18.518+0800 I STORAGE  [initandlisten] 
2018-02-27T15:03:18.518+0800 I STORAGE  [initandlisten] ** WARNING: Using the XFS filesystem is strongly recommended with the WiredTiger storage engine
2018-02-27T15:03:18.518+0800 I STORAGE  [initandlisten] **          See http://dochub.mongodb.org/core/prodnotes-filesystem
2018-02-27T15:03:19.055+0800 I CONTROL  [initandlisten] 
2018-02-27T15:03:19.055+0800 I CONTROL  [initandlisten] ** WARNING: Access control is not enabled for the database.
2018-02-27T15:03:19.055+0800 I CONTROL  [initandlisten] **          Read and write access to data and configuration is unrestricted.
2018-02-27T15:03:19.055+0800 I CO