[root@richard yum.repos.d]# mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

[root@richard yum.repos.d]# wget http://lug.ustc.edu.cn/wiki/_export/code/mirrors/help/centos?codeblock=2

[root@richard yum.repos.d]# wget http://lug.ustc.edu.cn/wiki/_export/code/mirrors/help/centos?codeblock=1

[root@NJZYY06 yum.repos.d]# yum clean all
Loaded plugins: aliases, changelog, downloadonly, fastestmirror, kabi, presto, refresh-packagekit, security, tmprepo, verify,
              : versionlock
Loading support for CentOS kernel ABI
Cleaning repos: base extras updates
Cleaning up Everything
Cleaning up list of fastest mirrors
11 delta-package files removed, by presto
[root@richard yum.repos.d]# yum makecache

Loaded plugins: aliases, changelog, downloadonly, fastestmirror, kabi, presto, refresh-packagekit, security, tmprepo, verify,

              : versionlock

Loading support for CentOS kernel ABI

base                                                                                                         | 9.4 kB     :

http://mirrors.ustc.edu.cn/centos/6/os/x86_64/repodata/repomd.xml: [Errno -1] Error importing repomd.xml for base: Damaged repomd.xml file

Trying other mirror.

Error: Cannot retrieve repository metadata (repomd.xml) for repository: base. Please verify its path and try again

[root@njzyy07 yum.repos.d]# yum makecache

Loaded plugins: aliases, changelog, downloadonly, fastestmirror, kabi, presto, refresh-packagekit, security, tmprepo, verify,

              : versionlock

Loading support for CentOS kernel ABI

Loading mirror speeds from cached hostfile

base                                                                                                         | 3.7 kB     :

base/group_gz                                                                                                |  kB     :

base/filelists_db                                                                                            | 5.9 MB     :

base/primary_db                                                                                              | 4.4 MB     :

base/other_db                                                                                                | 2.8 MB     :

extras                                                                                                       | 3.4 kB     :

extras/filelists_db                                                                                          |   kB     :

extras/prestodelta                                                                                           |   B     :

extras/primary_db                                                                                            |   kB     :

extras/other_db                                                                                              | 5.8 kB     :

updates                                                                                                      | 3.4 kB     :

updates/filelists_db                                                                                         | 2.2 MB     :

updates/prestodelta                                                                                          |  kB     :

updates/primary_db                                                                                           | 3.7 MB     :

updates/other_db                                                                                             |   MB     :

Metadata Cache Created

[root@richard yum.repos.d]# yum update