CentOS 7 VS CentOS 6

The difference between CentOS 7 and CentOS 6
(1)Desktop system
[CentOS6] GNOME 2.x
[CentOS7] GNOME 3.x (GNOME Shell)

(2)File system
[CentOS6] ext4
[CentOS7] xfs

(3)Kernel version< br>[CentOS6] 2.6.xx
[CentOS7] 3.10.xx

(4)Boot Loader
[CentOS6] GRUB Legacy (+efibootmgr) < br>[CentOS7] GRUB2

(5)Firewall
[CentOS6] iptables
[CentOS7] firewalld

< p>(6) Default database
[CentOS6] MySQL
[CentOS7] MariaDB

(7) File structure
[CentOS6] /bin, / sbin, /lib, and /lib64 under /
[CentOS7] /bin, /sbin, /lib, and /lib64 moved to /usr

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

(9) Time synchronization
[CentOS6]
$ ntp
$ ntpq -p

[CentOS7]
$ chrony
$ chronyc sources

(10) Modification time
[CentOS6]
$ vi m /etc/sysconfig/clock
ZONE=”Asia/Tokyo”
UTC=fales
$ sudo ln -s /usr/share/zoneinfo/Asia/Tokyo /etc/localtime

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

(11)Modify the region
[CentOS6]
$ vim /etc/sysconfig/i18n
LANG=”ja_JP.utf8″
$ /etc/sysconfig/i18n
$ locale

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

(12)Service related
1) Start and stop
[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

Auto start
[CentOS6]
$ chkconfig service_name on/off

[CentOS7]
$ systemctl enable service_name
$ systemctl disable service_name

Service list
[CentOS6]
$ chkconfig –list

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

Forced to stop
[Ce ntOS6]
$ kill -9

[CentOS7]
$ systemctl kill –signal=9 sshd

(13 )Network
1)Network information
[CentOS6]
$ netstat
$ netstat -I
$ netstat -n

[CentOS7]
$ ip n
$ ip -sl
$ ss

2) IP address MAC address
[CentOS6]
$ ifconfig -a

[CentOS7]
$ ip address show

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

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

(14) Restart and shut down
1) Shut down
[CentOS6]
$ shutdown -h now

[CentOS7]
$ poweroff
$ systemctl poweroff

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

[CentOS7]
$ reboot
$ systemctl reboot

3) Single user mode
[CentOS6]
$ init S

[CentOS7]
$ systemctl rescue

4) Startup mode
[CentOS6]
[GUICUI]
$ vim /etc/inittab
id :3:initdefault:
[CUIGUI]
$ startx

[CentOS7]
[GUICUI]
$ systemctl isolate multi-user.target
[CUIGUI] < br>$systemctl isolate graphical.target
Default
$ systemctl set-default graphical.target
$ systemctl set-default multi-user.target
Currently
$ systemctl get-default

Linux7 Modify the network configuration
still under /etc/sysconfig/network-scripts/

Linux7 yum related
1. Mount the package source CentOS7.iso to the system
mount /dev/cdrom /mnt
mount -t iso9660 -o loop /CentOS7.iso /mnt
2. Configure local yum source
vim /etc/yum.repos.d/CentOS- Media.repo
[rhel-media]
name=CentOS-$releasever-Media
baseurl=file:///mnt/
enabled=1
gpgcheck=0
gpgkey =file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
3. Use
yum clean all
yum list

Install graphical interface under Linux7 minimal environment yum groupinstall “X Window System” yum groupinstall “GNOME Desktop” yum groupinstall “Graphical Administration Tools” startx ln -sf /lib/systemd/system/runlevel5.target /etc/systemd/ system/default.target #Set the graphical interface as the default startup interface