The initial configuration of the system CENTOS7

1. System inconsistent time and time zone

1.1 Check System Time:

  [root@localhost sysconfig]# timedatectl     
  Local time: 一 2017-11-06 21:13:19 CST   
  Universal time: 一 2017-11-06 13:13:19 UTC        
  RTC time: 一 2017-11-06 13:13:19       
  Time zone: Asia/Shanghai (CST, +0800)    
  NTP enabled: noNTP synchronized: no 
  RTC in local TZ: no      
  DST active: n/a

1.2 View system time zone:

[root@localhost sysconfig]# ls /usr/share/zoneinfo/

Africa      Brazil   Egypt    GB-Eire    HST          Japan      Navajo    posixrules  Turkey     zone1970.tab
America     Canada   Eire     GMT        Iceland      Kwaj

1.3 delete the partition in which the current system:

[root@localhost sysconfig]# sudo rm /etc/localtime

1.4 to create a soft link from / usr / share / zoneinfo / to replace the current time zone information, directly select Universal ::

[root@localhost sysconfig]# sudo ln -s /usr/share/zoneinfo/Universal /etc/localtime

1.5 once again view the system time:

[root@localhost sysconfig]# sudo timedatectl

 Local time: 一 2017-11-06 13:14:32 UTC

 Universal time: 一 2017-11-06 13:14:32 UTC

 RTC time: 一 2017-11-06 13:14:32

 Time zone: Universal (UTC, +0000)

 NTP enabled: no

 NTP synchronized: no

 RTC in local TZ: no

 DST active: n/a

2. Network Settings

2.1 virtual machine settings editor to enter the three files (in order to)

vim /etc/sysconfig/network

# Created by anaconda

NETWORKING=yes

GATEWAY=192.168.50.2

vim /etc/sysconfig/network-scripts/ifcfg-ens33

TYPE=Ethernet
NAME=ens33
BOOTPROTO=static
NM_CONTROLLED=yes
IPV6INIT=no
ONBOOT=yes
IPADDR=192.168.50.10
PREFIX0=32
NETMASK=255.255.255.0
DNS1=192.168.50.2

vim /etc/resolv.conf

nameserver 192.168.50.2

2.2 Network Service Restart

systemctl restart network.service

3. The switching mirror source (Ali)

(1) image backup yum source (cd /etc/yum.repos.d)

[root@slave2 yum.repos.d]#mv /etc/yum.repos.d/CentOS-Base.repo  /etc/yum.repos.d/CentOS-Base.repo.backup

(2) Download aliyun the yum configuration file to /etc/yum.repos.d

[root@slave2 yum.repos.d]# wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo  

(3) generating the cache operation yum

[root@slave2 yum.repos.d]# yum makecache

(4) Update System

[root@slave2 yum.repos.d]# yum -y update

4. CENTOS unloading system comes java

查看CentOS自带JDK是否已安装:
yum list installed |grep java
卸载JDK相关文件输入:
yum -y remove java-1.8.0-openjdk*
卸载tzdata-java输入：
yum -y remove tzdata-java.noarch

5.java environment variable configuration

vim ~/.bashrc:

# .bashrc

# User specific aliases and functions

alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
JAVA_HOME=/usr/local/src/jdk1.8.0_172
CLASSPATH=.:/usr/local/src/jdk1.8.0_172/bin
PATH=$JAVA_HOME/bin:$PATH
export JAVA_HOME CLASSPATH PATH
# Source global definitions
if [ -f /etc/bashrc ]; then
        . /etc/bashrc
fi