Fix Slow YUM Updates on CentOS: Switch to Domestic Mirrors (Alibaba Cloud, Tencent Cloud)

Problem Background

When using the default YUM repositories on CentOS for software installation or system updates, connection speeds can be extremely slow or even time out due to network latency to overseas servers. Replacing the default YUM sources with domestic mirrors (such as Alibaba Cloud or Tencent Cloud) can significantly improve download speeds and operational efficiency.

Step-by-Step Guide

All following commands must be executed in a terminal with root privileges.

Step 1: Back Up the Original Repository Configuration

Before making any changes, it is strongly recommended to back up the original repository configuration file for potential recovery.

mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup

Step 2: Download and Replace with a Domestic Mirror

Choose the appropriate command based on your CentOS version to download the new repository configuration file.

Alibaba Cloud Mirror

• CentOS 6.x

  wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo

• CentOS 7.x

  wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

• CentOS 8.x

  wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-8.repo

Note: CentOS 8 reached End-of-Life in December 2021. It is recommended to upgrade to CentOS Stream, Rocky Linux, or AlmaLinux. Alibaba Cloud retains this repository for legacy systems.

Tencent Cloud Mirror

Tencent Cloud provides another stable and fast mirror option. Example for CentOS 7:

wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.cloud.tencent.com/repo/centos7_base.repo

For other versions (e.g., CentOS 6 or 8), visit the Tencent Cloud Mirror Site to find the corresponding repository file URL.

Step 3: Clean and Rebuild the YUM Cache

After changing the repository, clear the old cache and generate a new one to ensure the system recognizes the new mirror.

• Clean YUM Cache

  yum clean all

• Rebuild YUM Cache

  yum makecache

Verification and Next Steps

After completing the steps above, you can run yum update (in a non-production environment) or attempt to install a package to test if the speed has improved.

Additional Note: If you are using CentOS 7 with the EPEL repository enabled, it is also advisable to replace it with a domestic mirror. Use the following command:

wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo