In a netsplit, what does fencing achieve when done by a node that doesn't have quorum? It still won't have quorum. It should probably just clean up as best it can and leave the rest of the cluster alone. -steve -- Steve Landherr -- landherr@xxxxxxxxxx Kazeon Systems, Inc. Mountain View, California -----Original Message----- From: linux-cluster-bounces@xxxxxxxxxx [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of Michael Conrad Tadpol Tilstra Sent: Tuesday, August 03, 2004 9:13 AM To: Discussion of clustering software components including GFS Subject: Re: [Linux-cluster] GFS 6.0 node without quorum tries to fence So looking at what you gave below, mitte was master. (making this guess from the "Core lost slave quorum" part of the message below.) It knows that it doesn't have quorum, it still is going to try to be the Master. It does not know "that it can not build a cluster." The only thing it knows right now about the other nodes is that they failed to send heartbeats. Therefor they must have left the cluter abnormally. Therefor it must fence them. The other two nodes see that mitte have failed to reply to heartbeats. Therefor it must have left the cluster abnormally. Therefor it must be fenced. Both sides of the netsplit are trying to resolve things to regain the cluster. From an outsiders view point (which you and I have, the nodes do not.) We can see that mitte's attempts are futile, oben and unten will get control of the cluter. But the node cannot see this. This is what makes netsplits kind of ugly. (using ifdown to test cluster stuff causes extra confusion in my opinion. because you actually are creating a netsplit case. Not a simpler node down case. The power switch is nice for this.) I hope that made some sence. -- Michael Conrad Tadpol Tilstra Blood is thicker than water, and much tastier.
