How to Upgrade CentOS 7 to CentOS 8

James KiarieDecember 14, 2020November 11, 2019 CentOS 147 Comments

In this article, you will learn how to upgrade CentOS 7 to CentOS 8. The steps described herein do not depict the official upgrade and this should not be applied to a production server yet.

Step 1: Install the EPEL Repository

To start off, install the EPL repository by running:

# yum install epel-release -y

Step 2: Install yum-utils Tools

After successfully installing EPEL, install yum-utils by running the command below.

# yum install yum-utils

Thereafter, you need to resolves RPM packages by executing the command.

# yum install rpmconf
# rpmconf -a

Next, perform a clean-up of all the packages you don’t require.

# package-cleanup --leaves
# package-cleanup --orphans

Step 3: Install the dnf in CentOS 7

Now install dnf package manager which is the default package manager for CentOS 8.

# yum install dnf

You also need to remove the yum package manager using the command.

# dnf -y remove yum yum-metadata-parser
# rm -Rf /etc/yum

Step 4: Upgrading CentOS 7 to CentOS 8

We are now ready to upgrade CentOS 7 to CentOS 8, but before we do so, upgrade the system using the newly install dnf package manager.

# dnf upgrade

Next, install CentOS 8 release package using dnf as shown below. This will take a while.

# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-linux-repos-8-2.el8.noarch.rpm http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-linux-release-8.3-1.2011.el8.noarch.rpm http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8-2.el8.noarch.rpm

Next, upgrade the EPEL repository.

dnf -y upgrade https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm

After successfully upgrading the EPEL repository, remove all the temporary files.

# dnf clean all

Remove the old kernel core for CentOS 7.

# rpm -e `rpm -q kernel`

Next, be sure to remove conflicting packages.

# rpm -e --nodeps sysvinit-tools

Thereafter, launch the CentOS 8 system upgrade as shown.

# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync

Step 5: Install the New Kernel Core for CentOS 8

To install a new kernel for CentOS 8, run the command.

# dnf -y install kernel-core

Finally, install CentOS 8 minimal package.

# dnf -y groupupdate "Core" "Minimal Install"

Now you can check the version of CentOS installed by running.

# cat /etc/redhat-release

Conclusion

This article concludes on how you can upgrade from CentOS 7 to CentOS 8. We hope you found this insightful.

If you liked this article, then do subscribe to email alerts for Linux tutorials. If you have any questions or doubts? do ask for help in the comments section.

If You Appreciate What We Do Here On TecMint, You Should Consider:

TecMint is the fastest growing and most trusted community site for any kind of Linux Articles, Guides and Books on the web. Millions of people visit TecMint! to search or browse the thousands of published articles available FREELY to all.

If you like what you are reading, please consider buying us a coffee ( or 2 ) as a token of appreciation.

We are thankful for your never ending support.

147 thoughts on “How to Upgrade CentOS 7 to CentOS 8”

robinhood1995

February 25, 2021 at 8:12 pm
Had to add “–allowerasing” to make mine work?
```
# dnf install --allowerasing http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-linux-repos-8-2.el8.noarch.rpm http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-linux-release-8.3-1.2011.el8.noarch.rpm http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8-2.el8.noarch.rpm
```
Also, change “upgrade” to “install“.
```
# dnf -y upgrade https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
```
Reply
Marcel Link

February 23, 2021 at 2:58 am
I had the same problem and found a workaround:

disable AppStream repo
```
# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync
```
enable AppStream repo
```
# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync
```
Reply
- Atomizer
  
  February 25, 2021 at 9:32 am
  Thanks for the fix here is the command I used to get it to work:
```
# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync --disablerepo=appstream
```
  After the installation, I also ran:
```
# dnf update -y
# dnf install kernel
```
  Everything looks good after the reboot now, thanks again.
  Reply

I have upgraded centos 7.9 to centos 8.3.2011,

but it is still showing old kernel version.

[[email protected] 18:12:48 boot]# uname -srv
Linux 3.10.0-693.el7.x86_64 #1 SMP Tue Aug 22 21:09:27 UTC 2017

[[email protected] 18:13:04 boot]# rpm -qa | grep kernel | sort
kernel-4.18.0-240.10.1.el8_3.x86_64
kernel-core-4.18.0-240.10.1.el8_3.x86_64
kernel-headers-4.18.0-240.10.1.el8_3.x86_64
kernel-modules-4.18.0-240.10.1.el8_3.x86_64
kernel-tools-4.18.0-240.10.1.el8_3.x86_64
kernel-tools-libs-4.18.0-240.10.1.el8_3.x86_64

Jason

February 10, 2021 at 6:14 am

Alfista – You may see a section like “weak dependencies” that includes some of the packages that require these dependencies. Python3 and Perl stuff has to be removed.
Reply
Luca

February 8, 2021 at 2:48 pm

Hope to see the same guide for an upgrade from CentOS 7 to Rocky Linux 8 when will be available, this will save a lot of work in migration
Reply
- Ravi Saive
  
  February 9, 2021 at 10:14 am
  
  @Luca,
  
  Sure, once Rocky Linux 8 available, if instructions are there to upgrade from CentOS to Rocky Linux, will surely publish the guide on same..
  Reply
Alfista

February 5, 2021 at 3:33 pm

Hi,

I have a problem with transaction check:

Running transaction check
Error: transaction check vs depsolve:
(gcc >= 8 with gcc < 9) is needed by annobin-9.23-1.el8.x86_64
rpmlib(RichDependencies) = 3:10.3.27 if mariadb) is needed by mariadb-connector-c-3.1.11-2.el8_3.x86_64
(mariadb-connector-c-config = 3.1.11-2.el8_3 if mariadb-connector-c-config) is needed by mariadb-connector-c-3.1.11-2.el8_3.x86_64
rpmlib(RichDependencies) <= 4.12.0-1 is needed by mariadb-connector-c-3.1.11-2.el8_3.x86_64
(annobin if gcc) is needed by redhat-rpm-config-123-1.el8.noarch
rpmlib(RichDependencies) <= 4.12.0-1 is needed by redhat-rpm-config-123-1.el8.noarch
To diagnose the problem, try running: 'rpm -Va –nofiles –nodigest'.
You probably have corrupted RPMDB, running 'rpm –rebuilddb' might fix the issue.
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.

Please can you help me?

Thanks.
Reply
- FD
  
  March 2, 2021 at 5:32 am
```
# dnf remove mariadb*
```
  Delete mariadb then run upgrade again.
  Reply
  - Alfista
    
    March 2, 2021 at 12:37 pm
    
    Will, it does not delete all repositories? While I have follower one solution here on the net and the result was deleting all repositories and then I needed to add it manually and it was hard to get and install it back.
    
    Thanks.
    Reply

Got something to say? Join the discussion. Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.