How to Upgrade CentOS 7 to CentOS 8

by James Kiarie | Published: November 11, 2019 | Last Updated: February 7, 2020

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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

Install EPEL Repo in CentOS 7

Step 2: Install yum-utils Tools

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

# yum install yum-utils

Install yum-utils in CentOS 7

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

# yum install rpmconf
# rpmconf -a

Keep Default RPM Settings

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

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

Clean RPM Packages

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

Install dnf in CentOS 7

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

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

Remove Yum in CentOS 7

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

Upgrade CentOS 7

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-repos-8.1-1.1911.0.8.el8.x86_64.rpm
# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-release-8.1-1.1911.0.8.el8.x86_64.rpm
# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm

Next, upgrade the EPEL repository.

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

Upgrade EPEL Repository

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

CentOS 8 System Upgrade

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

Install Kernel in CentOS 8

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

Check CentOS Version

Conclusion

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

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Tags: CentOS Tips

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James Kiarie

This is James, a certified Linux administrator and a tech enthusiast who loves keeping in touch with emerging trends in the tech world. When I'm not running commands on the terminal, I'm taking listening to some cool music. taking a casual stroll or watching a nice movie.

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Adnan Harb says:

April 1, 2020 at 4:57 pm

I have a segmentation fault ins response to “dnf -y remove yum yum-metadata-parser .

What could be the solution?

Reply
Cartes says:

March 30, 2020 at 9:52 pm

Hi,

I’m really at a loss about a weird problem after “rebooting”. I find that my network config is messed up. The 1st NIC eth0 is now renamed en1sp0, and the network config is not respecting the ifcfg-enp1s0 file.
```
[[email protected] ~]# ifconfig
enp1s0: flags=4163  mtu 1500
        inet 192.168.1.63  netmask 255.255.255.255  broadcast 192.168.1.63
        inet6 fe80::1e1b:dff:fe73:465d  prefixlen 64  scopeid 0x20
```
Whereas, the ifcfg-enp1s0 says:
```
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=yes
IPV6_AUTOCONF=no
IPV6_DEFROUTE=no
IPV6_FAILURE_FATAL=no
NAME=enp1s0
DEVICE=enp1s0
ONBOOT=yes
IPADDR=192.168.1.63
#SUBNET=255.255.255.0
PREFIX=24
GATEWAY=192.168.1.64
DNS1=8.8.8.8
DNS2=8.8.4.4
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
```
I just couldn’t get it to respect these settings at all! I read many articles, which said that NetworkManager now controls these settings, but everything says it respects the ifcfg files in /etc/sysconfig/network-scripts.

So, can anyone help how the /32 address is coming up?

Reply
Cartes says:

March 30, 2020 at 1:01 am

Hi,

My Centos 7 install fails at the “dnf install” lines under Step 4:
[[email protected] ~]# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-repos-8.1-1.1911.0.8.el8.x86_64.rpm Last metadata expiration check: 0:01:17 ago on Mon 30 Mar 2020 01:11:24 AM +06. centos-repos-8.1-1.1911.0.8.el8.x86_64.rpm 17 kB/s | 12 kB 00:00 Error: Problem: conflicting requests - nothing provides centos-gpg-keys = 8.1-1.1911.0.8.el8 needed by centos-repos-8.1-1.1911.0.8.el8.x86_64 - nothing provides system-release = 8.1 needed by centos-repos-8.1-1.1911.0.8.el8.x86_64 [[email protected] ~]# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-release-8.1-1.1911.0.8.el8.x86_64.rpm Last metadata expiration check: 0:01:37 ago on Mon 30 Mar 2020 01:11:24 AM +06. centos-release-8.1-1.1911.0.8.el8.x86_64.rpm 25 kB/s | 21 kB 00:00 Error: Problem: conflicting requests - nothing provides centos-gpg-keys = 8.1-1.1911.0.8.el8 needed by centos-release-8.1-1.1911.0.8.el8.x86_64 - nothing provides centos-repos = 8.1-1.1911.0.8.el8 needed by centos-release-8.1-1.1911.0.8.el8.x86_64 [[email protected] ~]# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm Last metadata expiration check: 0:01:47 ago on Mon 30 Mar 2020 01:11:24 AM +06. centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm 41 kB/s | 11 kB 00:00 Error: Problem: problem with installed package centos-release-7-7.1908.0.el7.centos.x86_64 - package centos-gpg-keys-8.1-1.1911.0.8.el8.noarch conflicts with centos-release < 8.0-0.1905.0.10 provided by centos-release-7-7.1908.0.el7.centos.x86_64 - conflicting requests (try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages)
The previous command ran perfectly: [[email protected] ~]# dnf upgrade Extra Packages for Enterprise Linux 7 - x86_64 5.9 MB/s | 16 MB 00:02 Docker main Repository 32 kB/s | 28 kB 00:00 CentOS-7 - Base 5.1 MB/s | 10 MB 00:02 CentOS-7 - Updates 4.6 MB/s | 9.4 MB 00:02 CentOS-7 - Extras 80 kB/s | 259 kB 00:03 Dependencies resolved. Nothing to do. Complete!

What could be going wrong?

Reply
- Cartes says:
  
  March 30, 2020 at 1:23 am
  
  Solved it! The comment from “bartmantv” was really helpful!
  
  I stumbled upon another error that was solved by the “MonkeyPet” solution!
  
  Thank you, everyone!
  
  Reply
Duilio says:

March 29, 2020 at 5:02 am

I’m trying to upgrade centos, but I’m having problems after
```
# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync
```
Error: transaction check vs depsolve:
(gcc >= 8 with gcc < 9) is needed by annobin-8.78-1.el8.x86_64
rpmlib(RichDependencies) <= 4.12.0-1 is needed by annobin-8.78-1.el8.x86_64
(annobin if gcc) is needed by redhat-rpm-config-120-1.el8.noarch
rpmlib(RichDependencies) <= 4.12.0-1 is needed by redhat-rpm-config-120-1.el8.noarch
To diagnose the problem, try running: 'rpm -Va –nofiles –nodigest'.

I tried:
```
# dnf remove redhat-rpm-config
```
and also removed the package with issues in:
```
#  rpm -Va --nofiles --nodigest
```
and after that I did.
```
# rpm --rebuilddb
```
But, the same problem.

Tried:
```
# dnf clean packages
```
Tried again:
```
 
# dnf remove redhat-rpm-config     
```
and got:
No match for argument: redhat-rpm-config
No packages marked for removal.

Tried also
```
# dnf remove redhat-rpm-config-120-1.el8.noarch
```
but still the same problem.

Any help with what is the problem?

Reply
Leo says:

March 29, 2020 at 12:08 am

It’s pretty good, with minor flaws though:

Firstly, I ran into difficulty remove kernel rpm because I’m using vdo support. You have to remove that.

Then too, you must install all 3 centos-release/repos/keys rpm in one command since they are dependency loop, old school headache.

There are lots of transactions fail during ‘dnf upgrade‘ but basically because I’m using some 3rd party repos and I can fix that later.

Thanks anyway, it’s a good one.

Reply
forbiddenera says:

March 26, 2020 at 2:37 pm

Okay, it magically came back after I couldn’t even ssh, was dumping a random error. Came back to shell and I was able to fix the rest

still sketchy..! backup first / no production!

Reply
Antxon says:

March 13, 2020 at 12:36 am

Even if the process might work, it is not a tested procedure by Red Hat. Why not use Leapp, which is what Red Hat supports?

Reply
MonkeyPet says:

March 7, 2020 at 10:21 am

If you get into dependencies hell try:
```
# dnf install gdbm gdbm-libs --best --allowerasing
```
Reply
- forbiddenera says:
  
  March 26, 2020 at 1:58 pm
  
  This hint helped, I had to do this for GCC in my case.
  
  Reply
bartmantv says:

February 20, 2020 at 8:05 pm

I just did this myself had to modify the rpm installation step, this needs to be a single install command including all the files

So instead of this step:
```
# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-repos-8.1-1.1911.0.8.el8.x86_64.rpm
# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-release-8.1-1.1911.0.8.el8.x86_64.rpm
# dnf install http://mirror.centos.org/centos/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm
```
anonymous previously on Feb 7 stated this, so your update was close, it has to be one line for dependencies to work. I’ve escaped the newline so it can formatted for webpage use…
```
# dnf install http://less.cogeco.net/CentOS/8/BaseOS/x86_64/os/Packages/centos-repos-8.1-1.1911.0.8.el8.x86_64.rpm \
http://less.cogeco.net/CentOS/8/BaseOS/x86_64/os/Packages/centos-release-8.1-1.1911.0.8.el8.x86_64.rpm \
http://less.cogeco.net/CentOS/8/BaseOS/x86_64/os/Packages/centos-gpg-keys-8.1-1.1911.0.8.el8.noarch.rpm
```
Reply
- Alexey says:
  
  February 28, 2020 at 8:43 pm
  
  Thanks, this really helped
  
  Reply

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How to Upgrade CentOS 7 to CentOS 8

Step 1: Install the EPEL Repository

Step 2: Install yum-utils Tools

Step 3: Install the dnf in CentOS 7

Step 4: Upgrading CentOS 7 to CentOS 8

Step 5: Install the New Kernel Core for CentOS 8

Conclusion

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

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How to Upgrade CentOS 7 to CentOS 8

Step 1: Install the EPEL Repository

Step 2: Install yum-utils Tools

Step 3: Install the dnf in CentOS 7

Step 4: Upgrading CentOS 7 to CentOS 8

Step 5: Install the New Kernel Core for CentOS 8

Conclusion

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