mongoDB: Installing mongoDB on CentOS7

When I tried to install mongoDB by 'yum' command on CentOS7, but it failed due to no entry found on default repository.
So, I created repository file and retry installation.

[root@localhost ~]# vi /etc/yum.repos.d/mongodb-org.repo
[mongodb-org-3.4]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.4/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-3.4.asc


[root@localhost ~]# yum install -y mongodb-org

Now the attempt was successful, and I was able to run mongo!

[root@localhost ~]# mongo
MongoDB shell version v3.4.21
connecting to: mongodb://127.0.0.1:27017
MongoDB server version: 3.4.21
Server has startup warnings:
2019-07-17T22:57:35.959+0900 I CONTROL [initandlisten]
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten] ** WARNING: Access control is not enabled for the database.
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten] ** Read and write access to data and configuration is unrestricted.
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten]
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten]
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is 'always'.
2019-07-17T22:57:35.960+0900 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2019-07-17T22:57:35.961+0900 I CONTROL [initandlisten]
2019-07-17T22:57:35.961+0900 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is 'always'.
2019-07-17T22:57:35.961+0900 I CONTROL [initandlisten] ** We suggest setting it to 'never'
2019-07-17T22:57:35.961+0900 I CONTROL [initandlisten]