[CentOS] Upgrading CentOS from 7 to 8

Roberto Ragusa
Thu, 30 Sep 2021 10:00:53 -0000

On 9/29/21 3:24 PM, Gesti? Servidors wrote:
> Hi,
>
> I'm doing some tests of upgrading CentOS from 7 to 8 reading this
step-by-step guide:
https://netshopisp.medium.com/how-to-upgrade-linux-servecentos-7-to-centos-8-ec2db96a189b
>
> I'm trying this upgrade in a VM, so I can save "snapshots"
and restart in a past saved point. However, all my test ends wrong, exacly in
Step 4 when I run "rpm -e `rpm -q kernel`". Then, systems says that
some packages are kernel dependencies. After I remove that dependencies, I
can't remove kernel...

That specific step is probably useless.
Installing new kernels for Centos8 will sooner or later remove older kernels
coming form C7.
If you really want to do this manually you could specify the version on your
"rpm -e" command.

If you are not ready to tweak the process a bit while upgrading and just expect
a straightforward list of commands, well, as others have explained, there is no
guaranteed
script or method.
If instead you have enough familiarity with the system to work around the
obstacles,
"impossible" things can often be done: for example, years ago I've
managed to upgrade
a Fedora 16 from i386 to x86_64, and everybody was swearing it was impossible to
do.

Regards.

--
    Roberto Ragusa    mail at robertoragusa.it