[Pacemaker] Enable remote monitoring

[Dejan Muhamedagic]

Hi Arnold,

On Sun, Nov 11, 2012 at 07:37:29PM +0100, Arnold Krille wrote:
> On Sun, 11 Nov 2012 18:37:04 +0100 Dejan Muhamedagic
> <dejanmm at fastmail.fm> wrote:
> > On Fri, Nov 09, 2012 at 05:22:08PM +0100, Lars Marowsky-Bree wrote:
> > > On 2012-11-09T14:06:29, Dejan Muhamedagic <dejanmm at fastmail.fm>
> > > wrote:
> > > > > And also doesn't really help with getting the state/readiness of
> > > > > services the guest might provide.
> > > > Isn't it that one gets a login prompt only once the host reached a
> > > > certain run level?
> > > Services may start in the background. The console may either be
> > > text, graphical, or network only.
> > Hmm, I have yet to see a Linux/UNIX host without a console. And
> > that means quite some time ;-)
> 
> While (almost) all systems have some kind of console, not all systems
> stay at a text-console during runtime.

It seems like you are mixing things up. This is not about
watching a computer monitor. On Linux there's always a console
tty.

> If you want to watch  a
> linux-terminal-server, its not a text-console that is the primary
> screen.
> 
> And then watching the text-console for a login:-prompt tells you that
> the machine is up. "Pressing" enter tells you that the login-process is
> still answering. But that doesn't tell you whether the webserver on
> that machine is still working correctly.

That is not the point.

> Its not even telling you if
> the machine is reacting to network stuff. All it tells you is that some
> kind of system is started. So its actually only a little more then
> "virsh list |grep <machinename>" tells you.
> 
> Imho watching the console for monitoring a machine is as useless as it
> can get.

It tells you that a host is at a certain runlevel. The host is
ready for business, i.e. all other service at the particular
runlevel have been started. Otherwise, it wouldn't make sense
that it offers a login prompt. I don't know how it is with
systemd, perhaps systemd functions differently. Whether a
particular service is functioning properly or at all is up to the
monitor resource to find out.

Thanks,

Dejan

> Have fun,
> 
> Arnold



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