The article describes a way to move from Centos 8 to AlmaLinux. This is a hot topic because Centos 8 won’t be supported after December 2021 anymore.
https://ostechnix.com/migrate-to-almalinux-from-centos-8-using-almalinux-deploy-script/
This article describes very good and deeply the problem with Centos 8 and also its evolution from the beginning to today, when everyone using Centos 8 should make (should have made!) thoughts about the future of his systems.
https://thehackernews.com/2021/10/winter-is-coming-for-centos-8.html
To get a list of availale updates
yum -v check-update
To get a transaction list of last updates
yum -v history list
To get a list of changes during a transaction
yum history info <transactionID>
To remove obsolete kernel packages without questions
package-cleanup –oldkernels -y