問題所在
[root@cit-server6-s1-372 yum.repos.d]# yum makecache Loaded plugins: fastestmirror base | 5.6 kB 00:00:00 http://mirrors.163.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno -1] Error importing repomd.xml for base: Damaged repomd.xml file
Trying other mirror. One of the configured repositories failed (CentOS-7 - Base - 163.com), and yum doesn't have enough cached data to continue. At this point the only
safe thing yum can do is fail. There are a few ways to work "fix" this: 1. Contact the upstream for the repository and get them to fix the problem. 2. Reconfigure the baseurl/etc. for the repository, to point to a working upstream. This is most often useful if you are using a newer distribution release than is supported by the repository (and the packages for the previous distribution release still work). 3. Disable the repository, so yum won't use it by default. Yum will then
just ignore the repository until you permanently enable it again or use --enablerepo for temporary usage: yum-config-manager --disable base
4. Configure the failing repository to be skipped, if it is unavailable. Note that yum will try to contact the repo. when it runs most commands, so will have to try and fail each time (and thus. yum will be be much slower). If it is a very temporary problem though, this is often a nice compromise: yum-config-manager --save --setopt=base.skip_if_unavailable=true failure: repodata/repomd.xml from base: [Errno 256] No more mirrors to try. http://mirrors.163.com/centos/7/os/x86_64/repodata/repomd.xml: [Errno -1] Error importing repomd.xml for base: Damaged repomd.xml file
[root@cit-server6-s1-372 yum.repos.d]#
主要問題在於yum源問題。
最直接最暴力的方法
直接備份刪除/etc/yum.repo.d/路徑下所有repo文件，
然后從另一台正常運行的服務器上，拷貝CentOS-Base.repo內容到/etc/yum.repos.d/目錄下，
重命名（可忽略此步驟）文件為centos.repo，然后重新執行yum安裝、更新命令，正常可用。
不然參考下面解決辦法
下面開始解決問題：
下面這一段參考博客：https://blog.csdn.net/shaoqiufeng/article/details/78785806
1. 查看centos7.2系統本身所安裝的yum依賴包
[root@zf-test-web01-4 ~]# rpm -qa|grep yum
yum-plugin-fastestmirror-1.1.31-34.el7.noarch
yum-metadata-parser-1.1.4-10.el7.x86_64
yum-3.4.3-132.el7.centos.0.1.noarch
2. 卸載這些軟件包
[root@zf-test-web01-4 ~]# rpm -e yum-plugin-fastestmirror-1.1.31-34.el7.noarch --nodeps
warning: /etc/yum/pluginconf.d/fastestmirror.conf saved as /etc/yum/pluginconf.d/fastestmirror.conf.rpmsave
[root@zf-test-web01-4 ~]# rpm -e yum-metadata-parser-1.1.4-10.el7.x86_64 --nodeps
[root@zf-test-web01-4 ~]# rpm -e yum-3.4.3-132.el7.centos.0.1.noarch --nodeps
[root@zf-test-web01-4 ~]#
3. 進入centos鏡像網站找到自己對應系統需要的yum包
查看系統的命令：
[root@zf-test-web01-4 ~]# cat /etc/redhat-release
CentOS Linux release 7.2.1511 (Core)
查看系統的位數：
[root@zf-test-web01-4 ~]# file /bin/ls
/bin/ls: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=aa7ff68f13de25936a098016243ce57c3c982e06, stripped
4.下載yum依賴包
wget http://vault.centos.org/7.2.1511/os/x86_64/Packages/yum-plugin-fastestmirror-1.1.31-34.el7.noarch.rpm
wget http://vault.centos.org/7.2.1511/os/x86_64/Packages/yum-metadata-parser-1.1.4-10.el7.x86_64.rpm
wget http://vault.centos.org/7.2.1511/os/x86_64/Packages/yum-3.4.3-132.el7.centos.0.1.noarch.rpm
5. 安裝yum依賴包
[root@zf-test-web01-4 ~]# rpm -ivh yum-*
Preparing... ################################# [100%]
Updating / installing...
1:yum-metadata-parser-1.1.4-10.el7 ################################# [ 33%]
2:yum-plugin-fastestmirror-1.1.31-3################################# [ 67%]
3:yum-3.4.3-132.el7.centos.0.1 ################################# [100%]
[root@zf-test-web01-4 ~]#
6. 更新centos系統的repo文件
（-----------------------------------------------------
http://mirrors.ustc.edu.cn/help/centos.html（這個很有用）
http://mirrors.163.com/.help/centos.html（這個我嘗試了，不能正常使用）
這兩個網址先寫下來，后面要用，很重要！
------------------------------------------------------）
1）首先備份一下，免得誤操作 /etc/yum.repos.d/CentOS-Base.repo
http://mirrors.ustc.edu.cn/help/centos.html 現在這個網址用上了，可以說厲害了
什么？中科大校園網址？沒錯！
[root@zf-test-web01-4 yum.repos.d]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
2）選擇對應版本的 /etc/yum.repos.d/CentOS-Base.repo文件, 放入/etc/yum.repos.d/ 操作前請做好相應備份
如本人centos版本為7，所以使用版本7的內容。
拷貝上面這些內容，粘貼到yum.repos.d/CentOS-Base.repo里面。
3）運行以下命令生成緩存
[root@zf-test-web01-4 yum.repos.d]# yum clean all
Loaded plugins: fastestmirror
Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast
Cleaning repos: base extras updates
Cleaning up everything
Cleaning up list of fastest mirrors
[root@zf-test-web01-4 yum.repos.d]# yum makecache
Loaded plugins: fastestmirror
base | 3.6 kB 00:00:00
extras | 3.4 kB 00:00:00
updates | 3.4 kB 00:00:00
(1/12): base/7/x86_64/group_gz | 156 kB 00:00:00
(2/12): base/7/x86_64/filelists_db | 6.7 MB 00:00:01
(3/12): extras/7/x86_64/prestodelta | 71 kB 00:00:00
(4/12): extras/7/x86_64/primary_db | 145 kB 00:00:00
(5/12): extras/7/x86_64/filelists_db | 528 kB 00:00:00
(6/12): extras/7/x86_64/other_db | 97 kB 00:00:00
(7/12): updates/7/x86_64/prestodelta | 589 kB 00:00:00
(8/12): base/7/x86_64/primary_db | 5.7 MB 00:00:01
(9/12): base/7/x86_64/other_db | 2.5 MB 00:00:00
(10/12): updates/7/x86_64/primary_db | 4.5 MB 00:00:00
(11/12): updates/7/x86_64/other_db | 490 kB 00:00:00
(12/12): updates/7/x86_64/filelists_db | 2.7 MB 00:00:01
Determining fastest mirrors
Metadata Cache Created
7. 嘗試使用yum install vim能否成功安裝。
8.如果還有問題就執行以下幾個命令：
https://blog.csdn.net/orangleliu/article/details/40588799
參照網上的做法： （一般yum有變更都需要這兩個操作）
yum clean all
yum clean metadata
yum update
9.所有的錯誤基本都ok了，突然感覺牛逼了，有木有？
當然看到有朋友這樣留言，解決上面的所有問題。我沒有試過這個問題能不能這樣解決。這個方法看起來比較簡單，遇到同樣問題的朋友，可以先嘗試這種方法，試試有沒有作用。