F10 Fresh Vanilla Install with Updates Has Broken NetworkManager

[Dan Williams]

On Mon, 2009-03-16 at 21:45 -0400, Tom Lane wrote:
> Dan Williams <dcbw at redhat.com> writes:
> > On Sat, 2009-03-14 at 13:57 -0400, Tom Lane wrote:
> >> NM might be great for laptops, but it's both useless and pernicious in
> >> a static-IP environment.  In both F9 and F10 I've had to turn it off,
> >> and the single most annoying thing about it is *you can't really turn
> >> it off*.  There are pieces of it that keep coming to life anyway ...
> >> eg bz #455825 and the fact that it keeps demanding my VPN password
> 
> > If NM is off, it's not going to touch your resolv.conf.
> 
> That was what you told me at the time, ignoring the fact that it
> nonetheless *was* overwriting resolv.conf.  I do appreciate the fact
> that that behavior went away in F-10, though.

Again, like I've explained before, if NM is not running, it *will not*
touch your resolv.conf.  That's simply an impossibility.  If the
NetworkManager process isn't running, it cannot touch your resolv.conf
file.  Just like there aren't real-life zombies that eat your brains, NM
can't eat your resolv.conf when it's not running.

What you were complaining about was the behavior of NM to rewrite
resolv.conf when it *is* running.  If you stop NM, then NM takes the
network connections down, and *of course* it's going to clear out your
resolv.conf, because you don't have any active network connections! (and
thus you can't talk to nameservers anyway)  Thus, on reboot, you don't
have anything in /etc/resolv.conf.  Unless you've re-enabled the
'network' serivce that is (which you probably should have done if you
wanted networking), at which point DHCP should re-populate resolv.conf
for you.  If you use static IP, well, then you should have DNS1= and
DNS2= etc in your ifcfg files to keep your DNS information around in a
file that isn't modified by tons of stuff (including stuff other than
NM).

I don't know how many times I have to explain this.  /etc/resolv.conf
*cannot* be the canonical source for DNS information, because so many
services (including ones other than NM) update resolv.conf.  Even if you
don't run NM, if you've started some VPN and then your box crashes, you
won't have correct resolv.conf information when you reboot.  Same sort
of thing with NM.

Dan

> >> when I'm not using it to control the VPN.
> 
> > Are you sure it's asking for your VPN password?
> 
> Quite; it says my "network credentials have expired", or words to that
> effect (not at the machine right now) in a password popup dialog.
> Today I got as far as determining that this seems to be coming from
> nm-system-settings, which apparently is getting dbus events about
> vpn start/stop and is convinced that that's its turf even though
> the NetworkManager service is off.  Unless I'm missing something,
> there is no configuration knob provided to disable the dbus sniffer.
> So I'm down to rpm -e NetworkManager, which I have now done and will
> soon see if I still have a working system ...
> 
> 			regards, tom lane
>