#1 When updating firewalld with the firewall-cmd command, remember that a response of "success" does not mean the changes took effect. You still have to stop and restart the services. There are three ways of doing this: reboot the server, use systemctl stop firewalld; systemctl start firewalld, firewall-cmd --reload
#2 When trying to install an rpm package (e.g., rpm -ivh nameOfNewPackage), you can get this error:
"...existingPackageName is obsoleted by nameOfNewPackage..."
One solution to this is to uninstall the existingPackageName.
This command can uninstall packages:
rpm -e nameOfPackage
But sometimes it won't work when yum will. For example:
yum remove existingPackageName
The --force option when using "rpm -ivh" would likely not help in this situation until the existing package is removed. If yum remove is taking a great deal of time (e.g., because the repositories it was configured for are now unreachable, which can happen for a reason related to the very work that you were doing), you may want to do these steps:
yum clean all
mv *.repo ./backup
Now create a file.repo file for what you need in /etc/yum.repos.d/. The subsequent yum commands should happen relatively quickly because the mirrors and various repos won't be utilized. Remember however, all the configured repos won't be accessible after you do these steps on this server. If you want the server to be the same after you remove the package, bring the .repo files out of the /etc/yum.repos.d/backup directory and back into the /etc/yum.repos.d/.