Machine: Centos 7.6
GNOME: Version 3.28.2


Scenario:

USER A: Needs a break from work, clicks lock button on the top right hand side from the drop down menu. His machine is now locked.

USER B: Wants to use machine but he cant because the session is locked by USER A, there is no "Log in as another user" as it normally should be.


QUESTION: Why is the "Log in as another user" tab missing at a locked screen? How can this ability be enabled/disabled?

COMMENTS: I can ssh into the system and restart gdm and it would cause USER A's session to be killed and a login screen will prompt for a new session. i know that. i also know switching users from a terminal BUT for clarification purposes what i really want is the ability to be able to "Log in as another user" from the login screen. I've scoured google for a solution but to no avail.

lock is lock, user is still logged in, AND switch user is switch user, as I understand it. only one can be logged in at a time in the same "terminal". setup dummy terminals to use the same box, with one user who locked his log in and a different user wants to get in and use the same box (server) (?) while the other user is still logged in.

To be able to "log in as another user" the screen LOCKing utility you're using must be able to
It looks like the lock screen util your system is using cannot do that.

You can simulate it by hand, by:
logging in on a TEXT console and starting up another X session from there (startx with a :1 argument or such).
But for two users to be active at the same time on the same screen you will need two different X servers to be running.

Thanks for the reply. ctrl+Alt f2 or 3 are disabled in this particular system which means there is no way i can start a text terminal and start an xserver.
Its a tough one.

It mostly is ctrl-alt-F6 to switch to the single, active, text console, but systemd may have changed that too (one of the reasons I do not use systemd, it changed too many things I've been using for the last 30 years).

Otherwise you will have to use another screen saver (or probably - the other user must do so), because without access TO a text console a locked computer esssentially means:
Another user can NOT login when the system is locked!
I know the KDE screensaver/lock application (used to?) was able to do a switch to another user, but only when the login was done through kdm (as IT in fact did the switch, the lock utility only requested it from the still running instance of KDM.
But CentOS of course isn't using KDM as the graphical display/login manager.

I got around this at work by replacing gdm with lightdm.

Does lightdm change the look of the desktop? I have tried just about everything with get this working including reinstalling gdm and group installing "server with GUI". I am curious to see if this will help, If it does bring changes to the look of centos then unfortunately i wouldn't be able to try this due to project requirements.

The desktop, of course not, it's just a login manager. The login screen, yes, it's a different login screen.

There was a downloadable update specificly for CentOS4 via YUM...i will see if i can find the location for you.

Were you able to find it?