安装完CentOS 7 minimal后，无力吐槽，变化之大，，发现以前常用的一些命令都没有。
一、常用命令安装
查看anaconda-ks.cfg，原来是没装base group的包
[root@centos7 ~]# cat anaconda-ks.cfg #version=RHEL7# System authorization informationauth –enableshadow –passalgo=sha512# Use CDROM installation mediacdrom# Run the Setup Agent on first bootfirstboot –enableignoredisk –only-use=sda# Keyboard layoutskeyboard –vckeymap=us –xlayouts=’us’# System languagelang en_US.UTF-8 –addsupport=zh_CN.UTF-8# Network informationnetwork –bootproto=dhcp –device=eno16777736 –onboot=off –ipv6=autonetwork –hostname=localhost.localdomain# Root passwordrootpw –iscrypted $6$Zz5VMf1HPPRm0YRL$QSoaU9pAUApXMj9BXuK5qlUFGAfCv9Y/ylVGUcDYv.lrxfNodTiI/7DO1UR7carvL1EdgwQpuiwDt524f6.GR.# System timezonetimezone Asia/Chongqing –isUtc –nontp# System bootloader configurationbootloader –location=mbr –boot-drive=sdaautopart –type=lvm# Partition clearing informationclearpart –none –initlabel %packages@core # 这里只有core%end
[root@centos7 ~]# yum groupinstall base # 安装完后ifconfig、service、chkconfig等命令就都有了
二、运行级别切换
[root@centos7 ~]# cat /etc/inittab # 系统运行级别的设置方式也变化了# inittab is no longer used when using systemd.## ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM.## Ctrl-Alt-Delete is handled by /etc/systemd/system/ctrl-alt-del.target## systemd uses ‘targets’ instead of runlevels. By default, there are two main targets:## multi-user.target: analogous to runlevel 3# graphical.target: analogous to runlevel 5## To set a default target, run:## ln -sf /lib/systemd/system/<target name>.target /etc/systemd/system/default.target这里写的很明白了，做个软链修改默认运行级别
[root@centos7 system]# ll /lib/systemd/system/runlevel*.target # 系统0-6 7个运行级别，2 3 4 运行指向同一个文件lrwxrwxrwx 1 root root 15 Oct 11 03:51 /lib/systemd/system/runlevel0.target -> poweroff.targetlrwxrwxrwx 1 root root 13 Oct 11 03:51 /lib/systemd/system/runlevel1.target -> rescue.targetlrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel2.target -> multi-user.targetlrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel3.target -> multi-user.targetlrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel4.target -> multi-user.targetlrwxrwxrwx 1 root root 16 Oct 11 03:51 /lib/systemd/system/runlevel5.target -> graphical.targetlrwxrwxrwx 1 root root 13 Oct 11 03:51 /lib/systemd/system/runlevel6.target -> reboot.target
三、systemctl管理系统服务
systemctl可以看作是service和chkconfig的组合
jobchkconfig、servicesystemctl
服务状态
service httpd status
systemctl status httpd(服务详细信息)
systemctl is-active httpd(只显示是否active)
centos 7之前的版本都采用Sysvinit的系统启动进程管理体系，因为是串行的进程启动流程，可能因为某个进程的阻塞而影响启动过程。centos 7使用systemd。目标是尽可能启动更少进程；尽可能将更多进程并行启动（这是性能优于SysVinit的理念基础）。
更详解的systemd介绍
RHEL7/CentOS7默认运行级别和终端分辨率
U盘安装CentOS 7.0图文详解教程
U盘安装64位CentOS 6.5方法
Win7安装64位CentOS 6.4双系统详细图文教程
CentOS与Windows双系统安装注意事项记录
UEFI+GPT安装Windows8和CentOS双系统
Windows8.1和CentOS6.5双系统安装
本文永久更新链接地址：
通电话，旅行，重复一个承诺和梦想，
