how do i know i need a reboot after a console based "upgrade"?

[Tommy Trussell]

On 4/17/07, Gabriel Dragffy <dragffy at yandex.ru> wrote:
> Tomoki Taniguchi wrote:
> > when updating a system with the newest packages using the desktop
> > tools like synaptic,
> > if a package is upgraded that requires a reboot to take effect,
> > there is a little icon that shows up on the upper panel to let me know
> > i need to reboot.
> >
> >
> > on a server system,  if i do a "sudo apt-get upgrade" or "sudo aptitude upgrade"
> > is there anyway to know i need a reboot?
> >
> > is there a file that is flagged?
> > or does the upgrade process return something that i can catch using grep?
> > or better still is there a way to tell apt-get or aptitude to reboot the system
> > after an upgrade when necessary?
> >
> > TIA,
> > Tomoki Taniguchi
> >
>
> AFAIK if you do 'upgrade' then you shouldn't need to restart for the
> changes to take effect. If you do a 'dist-upgrade' then generally you
> will need to restart for the changes to take effect. I'm not aware of
> anything else that lets you know.

I don't think dist-upgrade vs upgrade matters UNLESS there has been a
change to a kernel or a kernel module.

If you install the package apticron (and get postfix set correctly)
your server will generate an email message telling you what to do. I
cannot recall now whether the apticron message told me to reboot after
the recent kernel upgrade (I already knew I should). After the more
recent update to a kdelibs package, apticron gave explicit directions
(in the email message) describing how to test and implement it.

The apticron package is highly recommended on any server, especially a
"headless" one.