[Linux-cluster] Preventing automatic poweron?

[Greg Forte]

Troels Arvin wrote:
> With a Red Hat Cluster Suite for RHEL 4, consisting of two cluster nodes
> (for fail-over), using HP ILOs for fencing:
> 
> 1) Both nodes are shut down, using "poweroff".
> 
> 2) Node 1 is started by pressing the power button.
>    I don't want Node 2 to start yet. <------
> 
> 3) After a little while, Node 1 fences Node 2, so that Node 2 starts.
> 
> How can I prevent this automatic power-on? I mean: Node 1 should be able
> to see that Node 2 is currently powered off, so there is no need to fence
> it(?).

Unplug it?  the problem is, in a 2-node cluster, node 1 by itself has 
quorum, so if node 2 is powered off then it considers it dead and tries 
to revive it by fencing.  You either need to bring node 1 back up in 
"non-cluster mode" (stop cman/rgmanager/etc) or take further steps to 
prevent node 2 from being powered on.

This is why I prefer external fencing agents - if I manually turn off a 
node, it stays off ;-)

can you cut off communications to node 2's ILO from node 1 temporarily?
(and programatically?  I assume you can physically yank the 
communications cable, but that's no better than unplugging the node)

-g