yum install softwaremane ##安装
repolist ##列出设定yum源信息
remove softwaremane ##卸载
list softwareman ##查看软件源中是否有此软件
list all ##列出所有软件名称
list installd ##列出已经安装的软件名称
list available ##列出可以用yum安装的软件名称
clean all ##清空yum缓存
search softwareinfo ##根据软件信息搜索软件名字
whatprovides filename ##在yum源中查找包含filename文件的软件包
update ##更新软件
history ##查看系统软件改变历史记录
reinstall softwarename ##重新安装
info softwarename ##查看软件信息
groups list ##查看软件组信息
groups info softwaregroup ##查看软件组内包含的软件
groups inatall softwaregroup ##安装组件
groups remove softwaregroup ##卸载组件
#############################下载软件#####################################
##建立yum源
搞一个和系统匹配的镜像文件到系统中
下载rhel-server-7.2-x86_64-dvd.iso文件
mkdir /iso ##在根下建立一个文件存放文件
mv /home/kiosk/Desktop/*.iso /iso ##防止删掉，备份
mkdir /source7.0 /source7.2
mount /iso/rhel-server-7.0-x86_64-dvd.iso /source7.0 ##把镜像里的文件移动到相应目录
mount /iso/rhel-server-7.2-x86_64-dvd.iso /source7.2
cd /etc/yum.repos.d/ ##软件仓库目录
mkdir /repobackup
mv * /repobackup
vim yum.repo ##编辑文件
%%编辑的内容
[source7.2]
name=source7.2
baseurl=file:///source7.2 ##
gpgcheck=0
yum clean all ##清空yum缓存
ls /source7.0/Packages/ |grep dhcp ##查看7.0的安装包里dhcp的安装包
dhcp-4.2.5-27.el7.x86_64.rpm
dhcp-common-4.2.5-27.el7.x86_64.rpm
dhcp-libs-4.2.5-27.el7.i686.rpm
dhcp-libs-4.2.5-27.el7.x86_64.rpm
yum install dhcp -y ##安装dhcp
####实验详细操作####
[root@foundation21 ~]# mkdir /iso
mkdir: cannot create directory ‘/iso’: File exists
[root@foundation21 ~]# mv /home/kiosk/Desktop/*.iso /iso
[root@foundation21 ~]# mkdir /source7.0 /source7.2
[root@foundation21 ~]# mount /iso/rhel-server-7.0-x86_64-dvd.iso /source7.0
mount: /dev/loop0 is write-protected, mounting read-only
[root@foundation21 ~]# mount /iso/rhel-server-7.2-x86_64-dvd.iso /source7.2
mount: /dev/loop1 is write-protected, mounting read-only
[root@foundation21 ~]# cd /etc/yum.repos.d/
[root@foundation21 yum.repos.d]# mkdir /repobackup
[root@foundation21 yum.repos.d]# mv * /repobackup
[root@foundation21 yum.repos.d]# vim yum.repo
[root@foundation21 yum.repos.d]# yum clean all
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
: manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Cleaning repos: source7.2
Cleaning up everything
[root@foundation21 yum.repos.d]# cd
[root@foundation21 ~]# yum install dhcp 安装dhcp
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
: manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
source7.2 | 4.1 kB 00:00
(1/2): source7.2/group_gz | 136 kB 00:00
(2/2): source7.2/primary_db | 3.6 MB 00:00
Resolving Dependencies
--> Running transaction check
---> Package dhcp.x86_64 12:4.2.5-42.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
================================================================================
Package Arch Version Repository Size
================================================================================
Installing:
dhcp x86_64 12:4.2.5-42.el7 source7.2 511 k
Transaction Summary
================================================================================
Install 1 Package
Total download size: 511 k
Installed size: 1.4 M
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : 12:dhcp-4.2.5-42.el7.x86_64 1/1
source7.2/productid | 1.6 kB 00:00
Verifying : 12:dhcp-4.2.5-42.el7.x86_64 1/1
Installed:
dhcp.x86_64 12:4.2.5-42.el7
Complete! ##显示这个就是安装成功##
################################共享yum源#############################################
（1）在本地yum源配置完成之后安装apache
yum install httpd ##共享
systemctl start httpd
systemctl enable httpd
systemctl stop firewalld
systemctl disable firewalld
mkdir /var/www/html/source7.0 /var/www/html/source7.2
（2）挂载镜像：
mount /iso/rhel-server-7.0-x86_64-dvd.iso /var/www/html/source7.0
mount /iso/rhel-server-7.2-x86_64-dvd.iso /var/www/html/source7.2
vim /etc/rc.d/rc.local ##永久挂载，开机启动
编辑：mount /iso/rhel-server-7.0-x86_64-dvd.iso /var/www/html/source7.0
mount /iso/rhel-server-7.2-x86_64-dvd.iso /var/www/html/source7.2
:wq
chmod +x /etc/rc.d/rc.local
（3）访问测试
在浏览器中输入地址：
ip/source7.0
172.25.254.20/source7.0
172.25.254.20/source7.2
（4）配置虚拟机:
rm -fr /etc/yum.repos.d/*
vim /etc/yum.repos.d/yum.repo
[source7.0]
name=source7.0
baseurl=http://172.25.254.19/source7.0
gpgcheck=0
配置文件完成后可以在虚拟机输入yum install dhcp进行下载
挂载是临时的，重启就没了。长期挂载就是如上写入文件。
[root@foundation21 ~]# df 重启之后可以看到已经挂载完成
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda3 307974224 17399728 290574496 6% /
devtmpfs 1868044 0 1868044 0% /dev
tmpfs 1881152 88 1881064 1% /dev/shm
tmpfs 1881152 8868 1872284 1% /run
tmpfs 1881152 0 1881152 0% /sys/fs/cgroup
/dev/sda1 505580 149472 356108 30% /boot
/dev/loop0 3654720 3654720 0 100% /var/www/html/source7.0
/dev/loop1 3947824 3947824 0 100% /var/www/html/source7.2
tmpfs 376232 12 376220 1% /run/user/1000
yum命令仅仅是对软件进行管理，rpm命令才是真正安装软件的,yum可以解决软件依赖性。
###########################清理临时文件####################################
监控命令： watch -n -1 ls -R /mnt/ -1
[root@localhost cron.d]# cd /usr/lib/tmpfiles.d ##切换路径
[root@localhost tmpfiles.d]# vim westos.conf ##.conf 临时文件的后缀 编辑临时文件删除脚本
[root@localhost tmpfiles.d]# cat westos.conf
d /mnt/westos 1777 root root 8s ##编写的内容 8s表示临时文件产生8秒后删除
[root@localhost tmpfiles.d]# systemd-tmpfiles --create /usr/lib/tmpfiles.d/* ##创建临时文件
[root@localhost tmpfiles.d]# touch /mnt/westos/uhfu ##建立一个
[root@localhost tmpfiles.d]# touch /mnt/westos/ff ##再建立一个
[root@localhost tmpfiles.d]# systemd-tmpfiles --clean /usr/lib/tmpfiles.d/* ##删除已经8秒的临时文件