标签：centos7
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 information auth --enableshadow --passalgo=sha512 # Use CDROM installation media cdrom # Run the Setup Agent on first boot firstboot --enable ignoredisk --only-use=sda # Keyboard layouts keyboard --vckeymap=us --xlayouts=‘us‘ # System language lang en_US.UTF-8 --addsupport=zh_CN.UTF-8 # Network information network --bootproto=dhcp --device=eno16777736 --onboot=off --ipv6=auto network --hostname=localhost.localdomain # Root password rootpw --iscrypted $6$Zz5VMf1HPPRm0YRL$QSoaU9pAUApXMj9BXuK5qlUFGAfCv9Y/ylVGUcDYv.lrxfNodTiI/7DO1UR7carvL1EdgwQpuiwDt524f6.GR. # System timezone timezone Asia/Chongqing --isUtc --nontp # System bootloader configuration bootloader --location=mbr --boot-drive=sda autopart --type=lvm # Partition clearing information clearpart --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.target lrwxrwxrwx 1 root root 13 Oct 11 03:51 /lib/systemd/system/runlevel1.target -> rescue.target lrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel2.target -> multi-user.target lrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel3.target -> multi-user.target lrwxrwxrwx 1 root root 17 Oct 11 03:51 /lib/systemd/system/runlevel4.target -> multi-user.target lrwxrwxrwx 1 root root 16 Oct 11 03:51 /lib/systemd/system/runlevel5.target -> graphical.target lrwxrwxrwx 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
| job | chkconfig、service | systemctl |
| 服务开机自启动 | chkconfig --level 3 httpd on | systemctl enable httpd |
| 服务不开机自启动 | chkconfig --level 3 httpd off | systemctl disable httpd |
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) |
| 所有服务的启动状态 | chkconfig --list | systemctl list-units --type=service |
| 启动服务 | service httpd start | systemctl start httpd |
| 停止服务 | service httpd stop | systemctl stop httpd |
| 重启服务 | service httpd restart | systemctl restart httpd |
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 https://www.huzs.net/?p=2180
本文出自 “the-way-to-cloud” 博客，请务必保留此出处http://iceyao.blog.51cto.com/9426658/1562564
标签：centos7
原文地址：http://iceyao.blog.51cto.com/9426658/1562564
