How to fix yum update on CentOS 7

CentOS 7 reached its end of life on 30 June 2024. Its official mirrors were switched off, so yum update and yum install fail with errors such as:

Could not resolve host: mirrorlist.centos.org
Cannot find a valid baseurl for repo: base/7/x86_64

The packages still exist in the CentOS archive (the "vault"). The fix is to point yum at an archive mirror. It takes one command.

1. Back up the repository file

sudo cp /etc/yum.repos.d/CentOS-Base.repo /root/CentOS-Base.repo.bak

2. Point yum at the archive

Copy and run this as a single command:

sudo sed -i \
  -e 's|^mirrorlist=|#mirrorlist=|g' \
  -e 's|^#\{0,1\}baseurl=http://mirror.centos.org/centos/\$releasever/|baseurl=http://linuxsoft.cern.ch/centos-vault/7.9.2009/|g' \
  /etc/yum.repos.d/CentOS-Base.repo

It disables the dead mirror list and sets the base, updates, extras and centosplus repositories to the CentOS 7.9 archive.

3. Refresh and update

sudo yum clean all
sudo yum makecache
sudo yum update -y

You can check the result with:

grep ^baseurl /etc/yum.repos.d/CentOS-Base.repo

Each line should now start with baseurl=http://linuxsoft.cern.ch/centos-vault/7.9.2009/.

If it still fails

• The error names another repository (for example epel): that repository was archived too. Disable it for now with sudo yum-config-manager --disable epel, or ask us for help.
• You prefer the official CentOS archive: replace http://linuxsoft.cern.ch/centos-vault/7.9.2009/ in the command above with https://vault.centos.org/7.9.2009/. Very old CentOS 7 installs may not trust its HTTPS certificate; the mirror above works over plain HTTP, and packages are still checked with the CentOS signing key.
• To undo: sudo cp /root/CentOS-Base.repo.bak /etc/yum.repos.d/CentOS-Base.repo

Plan a move to a supported system

The archive has no new security updates, and it never will. For anything exposed to the internet, move to a maintained system. AlmaLinux and Rocky Linux are the closest to CentOS (same commands, same package names), and Debian and Ubuntu are also available. You can pick any of them when you reinstall your VPS from the panel. A reinstall erases the server, so back up your data first.