原文连接：https://www.cnblogs.com/bethal/p/5945026.html

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CentOS 7 vs CentOS 6的不同
   (1)桌面系统
[CentOS6] GNOME 2.x
[CentOS7] GNOME 3.x（GNOME Shell）


(2)文件系统
[CentOS6] ext4
[CentOS7] xfs


(3)内核版本
[CentOS6] 2.6.x-x
[CentOS7] 3.10.x-x


(4)启动加载器
[CentOS6] GRUB Legacy (+efibootmgr)
[CentOS7] GRUB2


(5)防火墙
[CentOS6] iptables
[CentOS7] firewalld


(6)默认数据库
[CentOS6] MySQL
[CentOS7] MariaDB


(7)文件结构
[CentOS6] /bin, /sbin, /lib, and /lib64在/下
[CentOS7] /bin, /sbin, /lib, and /lib64移到/usr下


(8)主机名
[CentOS6] /etc/sysconfig/network
[CentOS7] /etc/hostname


(9)时间同步
[CentOS6]
$ ntp
$ ntpq -p


[CentOS7]
$ chrony
$ chronyc sources


(10)修改时间
[CentOS6]
$ vim /etc/sysconfig/clock
   ZONE="Asia/Tokyo"
   UTC=fales
$ sudo ln -s /usr/share/zoneinfo/Asia/Tokyo /etc/localtime


[CentOS7]
$ timedatectl set-timezone Asia/Tokyo
$ timedatectl status


(11)修改地区
[CentOS6]
$ vim /etc/sysconfig/i18n
   LANG="ja_JP.utf8"
$ /etc/sysconfig/i18n
$ locale


[CentOS7]
$ localectl set-locale LANG=ja_JP.utf8
$ localectl status


(12)服务相关


1）启动停止
[CentOS6]
$ service service_name start
$ service service_name stop
$ service sshd restart/status/reload


[CentOS7]
$ systemctl start service_name
$ systemctl stop service_name
$ systemctl restart/status/reload sshd


自启动
[CentOS6]
$ chkconfig service_name on/off


[CentOS7]
$ systemctl enable service_name
$ systemctl disable service_name


服务一览
[CentOS6]
$ chkconfig --list


[CentOS7]
$ systemctl list-unit-files
$ systemctl --type service


强制停止
[CentOS6]
$ kill -9 <PID>


[CentOS7]
$ systemctl kill --signal=9 sshd


(13)网络


1）网络信息
[CentOS6]
$ netstat
$ netstat -I
$ netstat -n


[CentOS7]
$ ip n
$ ip -s l
$ ss


2）IP地址MAC地址
[CentOS6]
$ ifconfig -a


[CentOS7]
$ ip address show


3）路由
[CentOS6]
$ route -n
$ route -A inet6 -n


[CentOS7]
$ ip route show
$ ip -6 route show


(14)重启关闭


1）关闭
[CentOS6]
$ shutdown -h now 


[CentOS7]
$ poweroff
$ systemctl poweroff


2）重启
[CentOS6]
$ reboot
$ shutdown -r now


[CentOS7]
$ reboot
$ systemctl reboot


3）单用户模式
[CentOS6]
$ init S


[CentOS7]
$ systemctl rescue


4）启动模式
[CentOS6]
[GUICUI]
$ vim /etc/inittab
  id:3:initdefault:
[CUIGUI]
$ startx


[CentOS7]
[GUICUI]
$ systemctl isolate multi-user.target
[CUIGUI]
$systemctl isolate graphical.target
默认
$ systemctl set-default graphical.target
$ systemctl set-default multi-user.target
当前
$ systemctl get-default