When I reboot I get a fresh login screen for several seconds? before the reboot starts

[Chris Green]

On Sun, Aug 25, 2024 at 08:22:16AM -0400, Robert Heller wrote:
> At Sun, 25 Aug 2024 13:44:49 +0200 "Ubuntu user technical support,? not 
> for general discussions" <ubuntu-users at lists.ubuntu.com> wrote: 
> 
> >
> > Hi!
> >
> > Le dim. 25 ao????t 2024 ???? 13:40, Chris Green <cl at isbd.net> a ????crit :
> >
> > > On Sun, Aug 25, 2024 at 10:55:25AM +0100, Chris Green wrote:
> > > > When I reboot my system (running xubuntu 24.04) either from the menus
> > > > or from the command line ('sudo reboot') the GUI shuts down and I get
> > > > my standard GUI login prompt for several seconds before the reboot
> > > > actually starts.
> > >
> > >
> > You may be seeing an old memory page from the login screen which is not
> > wiped by the reboot code... And then after some time gets replaced by
> > whatever is being drawn on it.
> 
> Actually not. I've seen this on other Linux systems. What is happening is the
> shutdown process stops/kills *user* processes, which means that a logged in
> user is logged out, that causes the xdm-ish process puts up a login screen (or
> for a non-gui system, the *getty process reverts to a console login prompt).
> This was generally more appearent in the olden days with slower systems (that
> took longer to complete the shutdown process).  As the op says, the login
> screen is quickly replaced with the shutdown/reboot process -- the xdm-ish
> or *getty process gets killed, etc.
> 
> This is harmless. The *first* thing (or nearly the first thing) in the
> shutdown process is to disable logins. So any short lived login screen or
> prompt will be ineffective.
> 
But in my ase (OP here) the login **is** effective, I can actually log
in again - ... and then it shuts down.

This is on a pretty fast system, a Fujitsu Esprimo Q957 (Intel I5
processor) with a 2TB SSD. The other xubuntu 24.04 system where I
don't see this symptom is probably a bit slower (but not much).

-- 
Chris Green