操作系统介绍和安装centos7
掌握GNU、GPL
一操作系统发展历史
1969 Unix 贝尔实验室
1986 Minix 教授谭宁邦
1986 类似uinx 斯托曼
目标: GNU项目--创建一个类似unix系统
公司: FSF自由软件基金会
规则: GPL通用许可协议
1) 所有代码信息必须是开源
2) 代码可以进行修改,必须进行说明
成绩: 软件(编辑软件 查询日志) 解释器(bash == shell) 内核 The Hurd(没开发好)
1991 内核 托瓦茨(芬兰大学学生)
GNU+内核==linux
二操作系统版本选择
乌班图ubuntu：桌面领域，图形界面，适合开发人员使用
红帽 redhat：服务器领域，收费，国企、外企使用的更多
centos：服务器领域（免费）互联网领域
debian：服务器领域（安全性）金融领域，上海使用的比较多
SUSE：服务器领域（网络服务器）实现网络功能
Fredora：测试操作系统
centos6部署cobbler openstack很难，但是在centos7上可以很好部署
注意新的红帽软件开发是对Fredora进行测试调整，发布新版redhat或者centos
三操作系统安装过程
虚拟环境的概念
1虚拟出来多个真实系统环境，可以充分利用硬件资源
2可以节省物理空间占用
（一）虚拟环境部署
安装虚拟软件
windows:vmware workstation 15（收费版，但是学习时一般使用破解版，具有快照功能，相当于月光宝盒）
注意windows10检查vmware版本，如果不符合要求，会提示下载vmware player（免费版），不要下载
Mac OS:vmware fusion
开启虚拟打印功能
编辑 --> 首选项 --> 设备 --> 开启虚拟打印功能
（二）操作系统安装
创建虚拟主机
系统位数的选择
32位系统(i386架构): 识别内存最多只能4G，64位系统(x86_64架构): 识别内存可以超过4G
我的电脑内存是8G，所以选择64位
下载系统镜像文件
安装版本是centos 7.6-1810
新版系统下载: https://developer.aliyun.com/mirror
旧版系统下载: http://vault.centos.org/
新版系统下载: https://developer.aliyun.com/mirror
旧版系统下载: http://vault.centos.org/
加载系统镜像文件
安装操作系统
Install centos7 --- 安装centos7系统
Test this media & install Centos7 --- 测试光盘介质并且安装系统
Troubleshooting --- 系统修复
修改网卡名
修改网卡名称为eth0，保持和工作环境一致，在centos7上默认是ens33
修改方法：
选择第1个选项install centos7
按tab 键，输入 net.ifnames=0 biosdevname=0
注意第1个有s，第2个没有
注意技巧：在虚拟机的编辑处可以进行粘贴，比如把上面的两条设置进行粘贴，net.ifnames=0 biosdevname=0
系统磁盘分区
灵活分区方案
/boot分区 类似系统分区, 启动分区 200M
swap分区 交换分区(硬盘空间 - 交换 -> 内存使用)
内存 <8G swap分区大小 = 1.5内存
内存>=8G swap分区大小 = 8G
/分区 20G~500G 40G
剩余空间不分
注意在生产中根分区40G就可以了
我的虚拟机内存为1G，设置交换分区为1.5G
系统网络和主机名称配置
地址: 10.0.0.200
掩码 255.255.255.0
网关 10.0.0.254
系统预装软件
注意最小化安装，左侧选择
centos6: 235
centos7: 1236
[c:\~]$ ssh 10.0.0.200 Connecting to 10.0.0.200:22... Connection established. To escape to local shell, press Ctrl+Alt+]. WARNING! The remote SSH server rejected X11 forwarding request. Last failed login: Tue Nov 26 17:41:56 CST 2019 from 10.0.0.1 on ssh:notty There was 1 failed login attempt since the last successful login. Last login: Tue Nov 26 17:40:18 2019 [root@centos7 ~]# ip address show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 00:0c:29:ea:b8:14 brd ff:ff:ff:ff:ff:ff inet 10.0.0.200/24 brd 10.0.0.255 scope global noprefixroute eth0 valid_lft forever preferred_lft forever inet6 fe80::951a:d6ce:9fbd:c7b7/64 scope link noprefixroute valid_lft forever preferred_lft forever
[root@centos7 ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 41922560 1513544 40409016 4% / devtmpfs 487048 0 487048 0% /dev tmpfs 497948 0 497948 0% /dev/shm tmpfs 497948 7788 490160 2% /run tmpfs 497948 0 497948 0% /sys/fs/cgroup /dev/sda1 201380 107080 94300 54% /boot tmpfs 99592 0 99592 0% /run/user/0 [root@centos7 ~]# mount /dev/cdrom /mnt/ mount: /dev/sr0 is write-protected, mounting read-only [root@centos7 ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 41922560 1513544 40409016 4% / devtmpfs 487048 0 487048 0% /dev tmpfs 497948 0 497948 0% /dev/shm tmpfs 497948 7788 490160 2% /run tmpfs 497948 0 497948 0% /sys/fs/cgroup /dev/sda1 201380 107080 94300 54% /boot tmpfs 99592 0 99592 0% /run/user/0 /dev/sr0 4480476 4480476 0 100% /mnt
最小化安装默认是没有yum命令的
[root@centos7 ~]# rpm -ivh /mnt/Packages/net-tools-2.0-0.24.20131004git.el7.x86_64.rpm warning: /mnt/Packages/net-tools-2.0-0.24.20131004git.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY Preparing... ################################# [100%] Updating / installing... 1:net-tools-2.0-0.24.20131004git.el################################# [100%] [root@centos7 ~]# ifc ifcfg ifconfig
[root@centos7 ~]# rpm -ivh /mnt/Packages/yum-3.4.3-161.el7.centos.noarch.rpm warning: /mnt/Packages/yum-3.4.3-161.el7.centos.noarch.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY Preparing... ################################# [100%] package yum-3.4.3-161.el7.centos.noarch is already installed
[root@centos7 ~]# df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda3 41922560 1515920 40406640 4% / devtmpfs 487048 0 487048 0% /dev tmpfs 497948 0 497948 0% /dev/shm tmpfs 497948 7788 490160 2% /run tmpfs 497948 0 497948 0% /sys/fs/cgroup /dev/sda1 201380 107080 94300 54% /boot tmpfs 99592 0 99592 0% /run/user/0 /dev/sr0 4480476 4480476 0 100% /mnt [root@centos7 ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 40G 1.5G 39G 4% / devtmpfs 476M 0 476M 0% /dev tmpfs 487M 0 487M 0% /dev/shm tmpfs 487M 7.7M 479M 2% /run tmpfs 487M 0 487M 0% /sys/fs/cgroup /dev/sda1 197M 105M 93M 54% /boot tmpfs 98M 0 98M 0% /run/user/0 /dev/sr0 4.3G 4.3G 0 100% /mnt [root@centos7 ~]# yum repolist Loaded plugins: fastestmirror Determining fastest mirrors Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=7&arch=x86_64&repo=os&infra=stock error was 14: curl#6 - "Could not resolve host: mirrorlist.centos.org; Unknown error" Loading mirror speeds from cached hostfile Loading mirror speeds from cached hostfile Loading mirror speeds from cached hostfile repo id repo name status base/7/x86_64 CentOS-7 - Base 0 extras/7/x86_64 CentOS-7 - Extras 0 updates/7/x86_64 CentOS-7 - Updates 0 repolist: 0
[root@centos7 ~]# mkdir /etc/yum.repos.d/bak [root@centos7 ~]# ls /etc/yum.repos.d/bak [root@centos7 ~]# mv /etc/yum.repos.d/* /etc/yum.repos.d/bak/ mv: cannot move ‘/etc/yum.repos.d/bak’ to a subdirectory of itself, ‘/etc/yum.repos.d/bak/bak’ [root@centos7 ~]# cd /etc/yum.repos.d/ [root@centos7 yum.repos.d]# ls bak [root@centos7 yum.repos.d]# cd bak/ [root@centos7 bak]# ls CentOS-Base.repo CentOS-Debuginfo.repo CentOS-Media.repo CentOS-Vault.repo CentOS-CR.repo CentOS-fasttrack.repo CentOS-Sources.repo [root@centos7 bak]# ll total 32 -rw-r--r--. 1 root root 1664 Nov 23 2018 CentOS-Base.repo -rw-r--r--. 1 root root 1309 Nov 23 2018 CentOS-CR.repo -rw-r--r--. 1 root root 649 Nov 23 2018 CentOS-Debuginfo.repo -rw-r--r--. 1 root root 314 Nov 23 2018 CentOS-fasttrack.repo -rw-r--r--. 1 root root 630 Nov 23 2018 CentOS-Media.repo -rw-r--r--. 1 root root 1331 Nov 23 2018 CentOS-Sources.repo -rw-r--r--. 1 root root 5701 Nov 23 2018 CentOS-Vault.repo [root@centos7 bak]# cd .. [root@centos7 yum.repos.d]# vim base.repo -bash: vim: command not found [root@centos7 yum.repos.d]# vi base.repo [root@centos7 yum.repos.d]# yum repolist Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile base | 3.6 kB 00:00:00 (1/2): base/group_gz | 166 kB 00:00:00 (2/2): base/primary_db | 3.1 MB 00:00:00 repo id repo name status base base 4,021 repolist: 4,021
[root@centos7 yum.repos.d]# cat base.repo [base] name=base enable=1 baseurl=file:///mnt gpgcheck=0
[root@centos7 ~]# yum search bash Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile ========================================== N/S matched: bash =========================================== bash-completion.noarch : Programmable completion for Bash libvirt-bash-completion.x86_64 : Bash completion script pcp-pmda-bash.x86_64 : Performance Co-Pilot (PCP) metrics for the Bash shell bash.x86_64 : The GNU Bourne Again shell Name and summary matches only, use "search all" for everything.
问题yum配置有误，跳过检查
[root@centos7 ~]# yum install bash-completion.noarch -y Loaded plugins: fastestmirror You have enabled checking of packages via GPG keys. This is a good thing. However, you do not have any GPG public keys installed. You need to download the keys for packages you wish to install and install them. You can do that by running the command: rpm --import public.gpg.key Alternatively you can specify the url to the key you would like to use for a repository in the \'gpgkey\' option in a repository section and yum will install it for you. For more information contact your distribution or package provider. Problem repository: base
[root@centos7 yum.repos.d]# yum install bash-completion.noarch -y Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile base | 3.6 kB 00:00:00 Resolving Dependencies --> Running transaction check ---> Package bash-completion.noarch 1:2.1-6.el7 will be installed --> Finished Dependency Resolution Dependencies Resolved ======================================================================================================== Package Arch Version Repository Size ======================================================================================================== Installing: bash-completion noarch 1:2.1-6.el7 base 85 k Transaction Summary ======================================================================================================== Install 1 Package Total download size: 85 k Installed size: 259 k Downloading packages: Running transaction check Running transaction test Transaction test succeeded Running transaction Warning: RPMDB altered outside of yum. Installing : 1:bash-completion-2.1-6.el7.noarch 1/1 Verifying : 1:bash-completion-2.1-6.el7.noarch 1/1 Installed: bash-completion.noarch 1:2.1-6.el7 Complete!
注意debian和乌班图的命令相似，掌握一个就会另外一个了