centos7和centos6的区别
最近发的文章，有人咨询我，说为啥不用centos7，而用centos6，这个跟个人习惯和生产环境元素决定的。centos7和6变化的就很大的。我收集了一些区别，给大家看看。
注意：生产环境推荐centos6.个人学习尝鲜可以7.
(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
$ vim /etc/sysconfig/clock
ZONE="Asia/Tokyo"
UTC=fales
$ sudo ln -s /usr/share/zoneinfo/Asia/Tokyo /etc/localtime
$ timedatectl set-timezone Asia/Tokyo
$ timedatectl status
(11)修改地区
$ vim /etc/sysconfig/i18n
LANG="ja_JP.utf8"
$ /etc/sysconfig/i18n
$ locale
$ localectl set-locale.utf8
$ localectl status
(12)服务相关
1）启动停止
$ service service_name start
$ service service_name stop
$ service sshd restart/status/reload
$ systemctl start service_name
$ systemctl stop service_name
$ systemctl restart/status/reload sshd
自启动
$ chkconfig service_name on/off
$ systemctl enable service_name
$ systemctl disable service_name
服务一览
$ chkconfig --list
$ systemctl list-unit-files
$ systemctl --type service
强制停止
$ kill -9
$ systemctl kill --signal=9 sshd
(13)网络
1）网络信息
$ netstat
$ netstat -I
$ netstat -n
$ ip n
$ ip -s l
$ ss
2）IP地址MAC地址
$ ifconfig -a
$ ip address show
3）路由
$ route -n
$ route -A inet6 -n
$ ip route show
$ ip -6 route show
(14)重启关闭
1）关闭
$ shutdown -h now
$ poweroff
$ systemctl poweroff
2）重启
$ reboot
$ shutdown -r now
$ systemctl reboot
3）单用户模式
$ init S
$ systemctl rescue
4）启动模式
[GUICUI]
$ vim /etc/inittab
id:3:initdefault:
[CUIGUI]
$ startx
$ systemctl isolate multi-user.target
$systemctl isolate graphical.target
默认
$ systemctl set-default graphical.target
$ systemctl set-default multi-user.target
当前
$ systemctl get-default