If you get error like “Failed to start Verify integrity of password and group files” it usually means some services are already removed and still the password and group file tracks them (with user and group names). To check which users no longer exist in the computer run following password checking command.
$ sudo pwck [sudo] password for dell: user 'kdm': directory '/var/lib/kdm' does not exist user 'xmms2': directory '/var/lib/xmms2' does not exist
The pwck command lists the users that no longer exist in the system. You can remove them completely (from the password file as well) run following command on each of the users or groups that is listed above.
$ sudo userdel kdm $ sudo groupdel kdm
After uninstalling the associated groups and users, the shadow service can be restarted.
$ sudo systemctl start shadow.service $ sudo systemctl status shadow.service
I hope these commands helped you get rid of “Failed to start Verify integrity of password and group files.” error.