[Linux-cluster] Fencing agents

[Lon Hohberger]

On Thu, 2005-08-04 at 12:32 +0400, Denis Medvedev wrote:
> >The main advantage that "automatic" fencing gives you over manual fencing is
> >that in the event that a fencing operation is required, your cluster can
> >automatically recover (on the order of seconds to minutes) instead of waiting
> >for user intervention (which can take minutes to hours to days depending on
> >how attentive the admins are :).    
> >
> >  
> >
> "recover"? You mean reboot? But if a machine need fencing, doesn't that 
> mean that something is inherently wrong with that machine and simple 
> reboot would't cure that?

recovery = The *cluster* can continue operation, not the *node*.

If the node is truly dead (maybe its CPU was fried from a bolt of
lightning), rebooting it doesn't hurt it.  If it was just a software or
network issue (e.g. kernel panic, router glitch), then the node should
be able to recover after its reboot and rejoin the cluster.

-- Lon