Split-Brain Situations are *very* critical for a two node setup, aspecially 
when you are using
shared media like disks drbd syncs and so on. 

For bigger clusters the problem is a bit more easy, bevause you get a quorum 
loss, if half the
nodes are "down" or disconnected. You can use the directive for the no_qurum 
(ignore, *stop*, fence)
to make that stable - the ressources are stopped, ehen you use the value stop 
for that directive.

For a two node setup you run the twonode quorum plugin, which does not stop the 
ressources in the
case of a split (if I got that correctly teh quorum is not lost). Thus both 
nodes *could* aquire the resources.

To come out of those problems you need to setup STONITH (server fencing) 
resources. In your
setup you would need something like a management board, remote power switch,... 
so one node
could switch-off or reboot the other one. 

Once the rebooted node comes up it should not automatically restart heartbeat, 
to avoid running into
a second split brain situation.




----- Original Nachricht ----
Von:     Doug Lochart <[EMAIL PROTECTED]>
An:      General Linux-HA mailing list <[email protected]>
Datum:   15.02.2008 03:40
Betreff: [Linux-HA] Split-Brain occurrence, what do I do now?

>
> I am really confused.  I am following a tutorial and I go right into a
> split brain.  I can't see how it would have been any different if I
> yanked the power cord versus yanking the cables.  I thought this is
> what heartbeat was supposed to handle?
> 
> How do I recover?  No data was lost as I was just doing an initial test.
> What is it I need to do to prevent a split-brain from happening again?
> 
> Is there a good place to go to read about avoiding this situation?
> Much of the info I have found jumps right in as if you are already a
> master of this stuff.
> In case you need them my configs follow:
> 
>> 

Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren
ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT FÜR ALLE NEUEINSTEIGER
Jetzt bei Arcor: günstig und schnell mit DSL - das All-Inclusive-Paket
für clevere Doppel-Sparer, nur  29,95 Euro  inkl. DSL- und ISDN-Grundgebühr!
http://www.arcor.de/rd/emf-dsl-2
_______________________________________________
Linux-HA mailing list
[email protected]
http://lists.linux-ha.org/mailman/listinfo/linux-ha
See also: http://linux-ha.org/ReportingProblems

Reply via email to