Despite using gentoo for several months and going through several upgrades, I find that I'm still confused about what system state is safe for emerge-ing. Often I'll have a full kde session up (with lots of HTML docs open) when I run "emerge --pretend --update world". At that point, I'm not sure whether I should quit my kde session before emerging things. Sometimes I want to proceed in steps to be cautious, and it's annoying that I can't easily refer back to the HTML docs. It would be helpful if the Gentoo handbook had some general advice about when it's safe to emerge. For example: - emerge mozilla while mozilla is running? (probably not...) - emerge alsa-libs while applications which might have loaded them are running? - emerge cups while a cupsd is running? - emerge bash from inside a bash shell? - emerge baselayout while a bunch of applications are running? - emerge coreutils, even though emerge itself probably uses them? - etc.
You can do all of this whenever you want and nothing will happen to your running programs. Try it!
That's good that there aren't any gotchas, but you didn't address my main point, which is that it would be helpful to say this in the handbook. Without knowing the details of how emerge works, it's not obvious that any of these things should be safe. Did I just overlook an explanation somewhere in the handbook?
If you've been usig Gentoo for a while, you probably have run `emerge portage` and it worked, didn't it? Bottom line, it does not matter.
