On 03/22/2013 02:42 AM, Prathyush wrote: > HI, > > > I have 3 node cluster with 1 vote each ,and decided to shut down the 2 > nodes for maintenance . > When a proper power off /init 0 given to two of the nodes ,i never loses > the quorum > When i am making force power off (switching off the power/pulling > the power cable) quorum was lost and services failed in the third node. > why this is happening... any idea That's the exactly as should be. When you have 3 node cluster, and first node goes down - it's irrelevant if it went down by standard shutdown or by pulling the cord, other two nodes still have enough votes to hold the quorum. But now you're on just 2 out of 3 votes and things get a little bit more complicated. If you shut down one of the remaining two nodes by standard shutdown procedure, cman service will announce that the node is leaving cluster (ccs_tool leave). Other node will now know that he's the only one left, and although it won't have quorum, it will continue to provide services. It does not have a reason not to, cluster was disassembled nicely. But, if you pull out power out of one of the two remaining nodes, simulating it's crash, it's OK for the remaining node to stop providing services. He just doesn't know what's happening to other node, other node could think the same and you would get split-brain scenario. One thing that could solve your problem is introduction of quorum disk, which would hold 2 votes, so in the latter scenario, one node that survives would make scsi reservation on quorum disk and would thus hold 3 out of 5 votes. What kind of fencing are you using? Is it IPMI? -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
