Sometimes you may encounter an error when updating or installing a program in CentOS. Stay tuned to this article in Radib so that we can fix this problem together.
The "Failed to download metadata for repo 'AppStream'" error in CentOS usually occurs for the following reasons:
- Lack of access to repositories or internet problems.
- Repositories are disabled or redirected.
- Using an old or unsupported version of CentOS.
1. Checking the Internet Connection
First, make sure the server is connected to the Internet:
ping -c 4 google.com
If the connection is not established:
- Check the network and DNS settings.
- Change the proxy to 8.8.8.8 (as described earlier).
2. Checking access to CentOS repositories
curl -I http://mirror.centos.org
If no proper response is received, the default repositories may no longer be available.
3. Clearing old repository cache
sudo dnf clean all
sudo rm -rf /var/cache/dnf
And then reload the repositories:
sudo dnf makecache
4. Enable and update repositories
sudo dnf update --refresh
If the problem persists, check the repository files:
sudo nano /etc/yum.repos.d/CentOS-Base.repo
Make sure the links are as follows:
baseurl=http://mirror.centos.org/centos/$releasever/AppStream/$basearch/os/
5. Replacing Repository Mirrors
Sometimes the default repositories may not be available. To solve this problem:
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Step 1: Install the alternative repository:
sudo dnf install epel-release
Step 2: Add alternative repositories:
sudo nano /etc/yum.repos.d/CentOS-Base.repo
And change Give:
baseurl=http://vault.centos.org/8.5.2111/AppStream/$basearch/os/
6. Update SSL and CA certificates
Sometimes the problem is due to invalid SSL certificates:
sudo dnf reinstall ca-certificates
sudo update-ca-trust
7. Check CentOS version
If you are running CentOS 8, please note that this version will no longer be supported by Red Hat as of 2021.
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- Recommended Solution: Migrate to CentOS Stream 8 or AlmaLinux.
- Install CentOS Stream:
sudo dnf install centos-release-stream
sudo dnf swap centos-linux-repos centos-stream-repos
sudo dnf distro-sync
Conclusion:
If the problem is not resolved after performing these steps, it is recommended to upgrade the operating system to newer versions or other equivalents such as AlmaLinux or Rocky Linux Upgrade.
Radib Group offers virtual servers with up-to-date operating systems and full support that can help resolve these types of issues faster.
