Centos 7 apps after upgrade

I have managed to successfully upgrade from Centos 7 to AlmaLinux 9.3 (with some tweaking), but when I loaded up after the upgrade, none of the apps that were loaded onto Centos 7 were present on the AlmaLinux distro.
Is that normal? Is there a way to do an inplace upgrade without losing all the apps and information on the Centos distro?


What do you mean by “apps that were loaded”?

I mean the apps that were installed on the Centos 7 server before the upgrade, such as docker.

I didn’t trust this scheme, made a backup and installed AlmaLinux 9.4 (although there were other reasons for this).

But the post-installation unexpectedly took more time - in particular, a number of applications that were immediately installed in CENTOS 7 by default, now
had to be installed manually.

You have to remember that RHEL 7, RHEL 8, and RHEL 9 are three different distros. (CentOS 7 was very similar to RHEL 7 and AlmaLinux 9 is not far from RHEL 9.)

The 9 has different set of packages (for same tasks) than the 7, or at least different versions and defaults.

If one wants about same features from 9 than what the 7 had, one has to find out the equivalent packages. Furthermore, one has to find out the appropriate configuration for the new versions.

That is not trivial even on fresh install. (Then again, if you have more than one system and come up with procedure, that is easy to scale out.)

The in-place conversion from one distro to an another has to do more. It has to remove all old packages, install replacements, and modify configurations – on “live” system and automatically.

Something like Docker is third-party. What to do to things that never were “part of CentOS 7”? There is only so much as even the best script knows to do.

There is podman that accepts Docker commands. You can install it.

I think I got lucky, i installed a new version of Docker and it was able to work. The container that was being run by docker was still there.
I’m hoping the same will happen on the other servers that have atlassian jira and bitbucket running.