紅帽 redhat 更改yum源爲本地光盤（cdrom）

學習Linux安裝tree命令，發現紅帽默認無法使用yum。查詢資料瞭解到修改yum源的方法如下：

1. 在/mnt目錄下增加一個cdrom目錄進行掛載；
2. 編輯/etc/yum.repos.d 下的repo文件。
3. 具體步驟如下：

---

1. 默認安裝yum報錯，如下

[root@localhost ~]# yum install tree
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
There are no enabled repos.
 Run "yum repolist all" to see the repos you have.
 To enable Red Hat Subscription Management repositories:
     subscription-manager repos --enable <repo>
 To enable custom repositories:
     yum-config-manager --enable <repo>

1. 創建一個掛載點。

   [root@localhost ~]# mkdir /mnt/cdrom
   [root@localhost ~]# mount /dev/cdrom /mnt/cdrom/
   [root@localhost ~]# ll /mnt/cdrom/
   total 962
   dr-xr-xr-x. 4 root root   2048 Oct 10  2018 addons
   dr-xr-xr-x. 3 root root   2048 Oct 10  2018 EFI
   -r--r--r--. 1 root root   8266 Apr  4  2014 EULA
   -r--r--r--. 1 root root   1455 Oct 10  2018 extra_files.json
   -r--r--r--. 1 root root  18092 Mar  6  2012 GPL
   dr-xr-xr-x. 3 root root   2048 Oct 10  2018 images
   dr-xr-xr-x. 2 root root   2048 Oct 10  2018 isolinux
   dr-xr-xr-x. 2 root root   2048 Oct 10  2018 LiveOS
   -r--r--r--. 1 root root    114 Oct 10  2018 media.repo
   dr-xr-xr-x. 2 root root 931840 Oct 10  2018 Packages
   dr-xr-xr-x. 2 root root   4096 Oct 10  2018 repodata
   -r--r--r--. 1 root root   3375 Sep 21  2018 RPM-GPG-KEY-redhat-beta
   -r--r--r--. 1 root root   3211 Sep 21  2018 RPM-GPG-KEY-redhat-release
   -r--r--r--. 1 root root   1796 Oct 10  2018 TRANS.TBL

3.進入repos目錄，創建repo文件，增加cdrom源，“RPM-GPG-KEY-redhat-release”該名稱從cdrom目錄中查找。

[root@localhost ~]# cd /etc/yum.repos.d/
    [root@localhost yum.repos.d]# ls
    redhat.repo
    [root@localhost yum.repos.d]# mv redhat.repo redhat.repo.bak
    [root@localhost yum.repos.d]# vi iso.repo
    [root@localhost yum.repos.d]# cat iso.repo
    [base]
    name=centos
    baseurl=file:///mnt/cdrom
    enable=1
    gpgcheck=0
    gpgkey=file:///mnt/cdrom/RPM-GPG-KEY-redhat-release

4.清理yum：yum clean all
5.安裝tree命令

    [root@localhost yum.repos.d]# yum -y install tree
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-manager
This system is not registered with an entitlement server. You can use subscription-manager to register.
base                                                              | 4.3 kB  00:00:00
(1/2): base/group_gz                                              | 146 kB  00:00:00
(2/2): base/primary_db                                            | 4.2 MB  00:00:00
Resolving Dependencies
--> Running transaction check
---> Package tree.x86_64 0:1.6.0-10.el7 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

=========================================================================================
 Package           Arch                Version                   Repository         Size
=========================================================================================
Installing:
 tree              x86_64              1.6.0-10.el7              base               46 k

Transaction Summary
=========================================================================================
Install  1 Package

Total download size: 46 k
Installed size: 87 k
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : tree-1.6.0-10.el7.x86_64                                              1/1
base/productid                                                    | 1.6 kB  00:00:00
  Verifying  : tree-1.6.0-10.el7.x86_64                                              1/1

Installed:
  tree.x86_64 0:1.6.0-10.el7

Complete!

6.至此修改yum源爲本地完成。