OS
# lsb_release -a
LSB Version: :core-4.0-amd64:core-4.0-ia32:core-4.0-noarch:graphics-4.0-amd64:graphics-4.0-ia32:graphics-4.0-noarch:printing-4.0-amd64:printing-4.0-ia32:printing-4.0-noarch
Distributor ID: CentOS
Description: CentOS release 5.8 (Final)
Release: 5.8 <==太舊了
Codename: Final

# yum install package
Loaded plugins: fastestmirror
Determining fastest mirrors
YumRepo Error: All mirror URLs are not using ftp, http[s] or file.
Eg. Invalid release/
removing mirrorlist with no valid mirrors: /var/cache/yum/base/mirrorlist.txt
Error: Cannot find a valid baseurl for repo: base

我以為是我的yum 壞掉了，到repository去看才知道是停止支援。該版本的目錄還在，只是沒檔案，留了一個字條：

This directory (and version of CentOS) is depreciated. CentOS-5 is now past EOL You can get the last released version of centos 5.11 here: http://vault.centos.org/5.11/ Please NOTE: this is not being maintained for security since moving to Vault. It will have security issues, you should upgrade to a new version instead.
好的，至少還有「遺跡」可以用。

修改
# vi /etc/yum.repos.d/CentOS-Base.repo

[base]
name=CentOS-$releasever – Base
baseurl=http://vault.centos.org/5.11/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#released updates
[updates]
name=CentOS-$releasever – Updates
baseurl=http://vault.centos.org/5.11/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

#additional packages that may be useful
[extras]
name=CentOS-$releasever – Extras
baseurl=http://vault.centos.org/5.11/extras/$basearch/

gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-5

把原本的註解或刪掉，加上上面黃色的。

勉強能用