配置 RHEL 使用本地源（光盘）
创建目录，并将 RHEL 光盘内容复制到该目录中；
[it@pxesvr ~]$ sudo mkdir /os
[sudo] password for it:
[it@pxesvr ~]$ sudo cp -r /run/media/it/RHEL-8-0-0-BaseOS-x86_64/* /os/
配置 yum 源配置文件，更改 baseurl，指定到刚刚创建的目录中的 BaseOS 和 AppStrem；
[it@pxesvr ~]$ sudo vim /etc/yum.repos.d/redhat.repo
[it@pxesvr ~]$ grep -v ^# /etc/yum.repos.d/redhat.repo
[localREPO]
name=localhost8
baseurl=file:///os/BaseOS
enable=1
gpgcheck=0
[localREPO_APP]
name=localhost8_app
baseurl=file:///os/AppStream
enable=1
gpgcheck=0
清除存储库中的所有临时文件，然后下载并缓存所有已知的存储库。
[it@pxesvr ~]$ sudo yum clean all
Updating Subscription Management repositories.
Unable to read consumer identity
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
0 files removed
[it@pxesvr ~]$ sudo yum makecache
Updating Subscription Management repositories.
Unable to read consumer identity
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
localhost8 25 MB/s | 2.2 MB 00:00
localhost8_app 54 MB/s | 5.3 MB 00:00
Metadata cache created.
测试（可以查询库中可用的软件包）
[it@pxesvr ~]$ yum list bind
Not root, Subscription Management repositories not updated
Last metadata expiration check: 5:53:29 ago on Mon 12 Oct 2020 11:04:43 AM CST.
Available Packages
bind.x86_64 32:9.11.4-16.P2.el8 localREPO_APP
