How do you know when a reboot is required after yum update?

[Raman Gupta]

> Donald Russell wrote:
> There have been times though when "things seemed odd" after a
> particularly large number of updates were applied... rather than spend
> untold amounts of time trying to solve them, I did a quick reboot...
> perhaps that was overkill, but it definitely caused all processes to
> restart.

One quick way to see which processes are using older (deleted) files
is a script I found on fedora-devel-list called "wasted-ram-updates.py":

http://markmail.org/message/dodinyrhwgey35mh

After updates, I always run this to see which processes need to be
restarted. Note that a few entries in this list are "normal" e.g. a
program opens a file for temporary storage, and then deletes it (but
keeps the handle), but most will indicate a process that needs to be
restarted to reload files from a new package.

Depending on the process, a service or application restart may be
enough, or if X/Gnome/KDE files have been updated, a restart of the X
server may be required. I think the only times I have ever required a
total reboot are kernel updates.

Cheers,
Raman