How to clone CentOS 7.7 installation on another disk?

I thought I could clone a running CentOS 7.7 installation by replicating the contents of the /, /boot, /boot/efi partitions on the target disk and then modifying the /etc/fstab and the grub.cfg files to allow for the UUID changes. Evidently there is something I am missing since the cloned disk boots up OK except for login processing. The tigerVNC server has been successfully cloned and I can remotely login to the cloned installation. The symptoms are I don’t get the usual login prompt on the main console, and when I try to login with ssh, I am prompted for the user id and then the password, but when I enter the password I get the response back “/bin/bash: Permission denied.” Similarly, when I boot to run level 3, after entering the password it loops back to the login: prompt. So, most everything is working except for password authentication. Relevant output from journalctl are: systemd-logind: Failed to start user slice user-42.slice, ignoring: Access denied (org.freedesktop.DBus.Error.AccessDenied) systemd-logind: Failed to start session scope session-c1.scope: Access denied gdm-launch-environment]: pam_systemd(gdm-launch-environment:session): Failed to create session: Access denied gdm-launch-environment]: pam_unix(gdm-launch-environment:session): session opened for user gdm by (uid=0) Querying systemd-logind status returns “active (running)” and also says “Started Login Service” I will appreciate any idea on what it is that I have overlooked.