Đến ngày 30/11/2020 Centos 6 đã kết thúc vòng đời và dừng hỗ trợ update, vì vậy khi chạy yum update sẽ bị lỗi

Loaded plugins: fastestmirror, refresh-packagekit, security

Setting up Update Process

Determining fastest mirrors

YumRepo Error: All mirror URLs are not using ftp, http[s] or file.

Eg. Invalid release/repo/arch combination/

removing mirrorlist with no valid mirrors: /var/cache/yum/x86_64/6/base/mirrorlist.txt

Error: Cannot find a valid baseurl for repo: base

Để khắc phục lỗi này chúng ta cần edit lại repo sang vault theo hướng dẫn sau:

1. Backup lại file repo cũ

cp /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo_bk

2. Edit lại file repo CentOS-Base.repo

[base]
name=CentOS-$releasever - Base
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/os/$basearch/
baseurl=https://vault.centos.org/6.10/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

# released updates
[updates]
name=CentOS-$releasever - Updates
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/updates/$basearch/
baseurl=https://vault.centos.org/6.10/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

# additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
# mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
# baseurl=http://mirror.centos.org/centos/$releasever/extras/$basearch/
baseurl=https://vault.centos.org/6.10/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-6

3. Xóa cache

yum clean all

4. Chạy lại lệnh update

yum update

Chúc các bạn thành công!