The system of Aliyun CentOS 5 can not install application software with yum.
Reason: CentOS 5 has ended its support from March 31, 2017, and no maintenance updates are provided. Therefore, the files including Ali Cloud Mirror Station may be out of date or some of them are missing.
Environment: CentOS 5. X
Method
1. Keep only / etc/yum.repos.d/CentOS-Base.repo other files either deleted or suffixed
2. Edit the file/etc/yum.repos.d/CentOS-Base.repo and replace mirrors.aliyun.com/centos/$release ever with the corresponding historical source address and version number, such as vault.centos.org/5.11
Full File Download http://tadown.com/fs/6x1idado5g5g9vdip0/
[base] name=CentOS-$releasever - Base failovermethod=priority baseurl=http://vault.centos.org/5.11/os/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-5 http://mirrors.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-5 #released updates [updates] name=CentOS-$releasever - Updates failovermethod=priority baseurl=http://vault.centos.org/5.11/updates/$basearch/ http://mirrors.aliyuncs.com/centos/$releasever/updates/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-5 http://mirrors.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-5 #additional packages that may be useful [extras] name=CentOS-$releasever - Extras failovermethod=priority baseurl=http://vault.centos.org/5.11/extras/$basearch/ http://mirrors.aliyuncs.com/centos/$releasever/extras/$basearch/ gpgcheck=1 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-5 http://mirrors.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-5 #additional packages that extend functionality of existing packages [centosplus] name=CentOS-$releasever - Plus failovermethod=priority baseurl=http://vault.centos.org/5.11/centosplus/$basearch/ http://mirrors.aliyuncs.com/centos/$releasever/centosplus/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-5 http://mirrors.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-5 #contrib - packages by Centos Users [contrib] name=CentOS-$releasever - Contrib failovermethod=priority baseurl=http://vault.centos.org/5.11/contrib/$basearch/ http://mirrors.aliyuncs.com/centos/$releasever/contrib/$basearch/ gpgcheck=1 enabled=0 gpgkey=http://mirrors.aliyun.com/centos/RPM-GPG-KEY-CentOS-5 http://mirrors.aliyuncs.com/centos/RPM-GPG-KEY-CentOS-5
3. Confirm that there are no repo-terminated files in the / etc/yum.repos.d/ directory except CentOS-Base.repo, and delete them if necessary, then execute Yum clean all & Yum makecache updates and enable new Yum sources.