CentOS官方宣告，于2017年4月份停止CentOS 5的支持，此后该系统将无法安装和更新软件，这意味着即使发现重大的漏洞也无法及时通过补丁进行修补，建议用户改用CentOS 7系统。

我司会继续为使用CentOS 5操作系统的用户提供技术支持，但有可能因为官方源停止了更新，导致部分功能无法安装使用时，敬请理解。

以下为原文：

CentOS 5 has reached end of life upstream. 

As there will be no more fixes for RHEL 5 released public upstream by Redhat then there will be no more updates for CentOS 5 either. You are encouraged to migrate any remaining systems to CentOS 7 or to CentOS 6 (which itself enters Production Phase 3 upstream in May 2017 with End of Life coming in 2020).

Expect the current CentOS 5 mirror content to migrate to vault.centos.org in the near future.

This notice was originally posted when CentOS 5 had one year of supported life left. It now has 6 1 month 1 week. You are encouraged to put your migration plans into action now if you haven't already done so. CentOS 6 goes EOL in 2020, CentOS 7 in 2024.

官方原文：https://www.centos.org/forums/viewtopic.php?f=9&t=57398