[Cluster-devel] unfencing

[David Teigland <teigland@redhat.com>]

On Mon, Feb 23, 2009 at 07:31:29PM +0100, Fabio M. Di Nitto wrote:
> Given this last example, a reasonable unfence operation would be to try
> to poweron via apc too.
> 
> There is no guarantee that it was only method="1" fencing the node and
> the node could be powered off.
> 
> if we succeed in enabling the switch port, we still don't guarantee that
> the node will come back because of lack of power..
> 
> How do we protect a node that failed to be fenced, from being unfenced?
> 
> Example 2:
> both method="1" and method="2" fail to fence node X.
> At this point any unfence operation is extremely dangerous.

A node unfences *itself* when it boots up.  As such, power-unfencing doesn't
make sense; unfencing is only meant to reverse storage fencing.

Dave