I have the below scenario, I have made the first node down the service failover to second node,then I switched off second node ,service again swiched to third node,the quorum was not lost,it adjusted automatically On Mar 22, 2013 9:11 PM, "Digimer" <[email protected]> wrote:
> This is correct. > > Quorum needs "50% + 1" of the votes. So in Prathyush's cluster of 3 > nodes/3 votes; > > 3 / 2 == 1.5 rounded up is 2. > > So once the second node shut down, quorum was lost. With quorum lost, the > remaining node will stop all of it's clustered services because it can no > longer be sure what the other nodes are doing. For example, the other two > nodes might turn back on, fail to connect to the one remaining node, decide > they have quorum and start clustered services. This would lead to a split > brain. > > If you want a 3-node cluster to work with just one node, consider adding a > quorum disk, assuming you have a SAN. This would add 2 votes to the > cluster. So the new math would be; > > 5/2 == 2.5 rounded up to 3. > > The quorum disk would give it's two votes to the remaining single node for > a total of 3 votes, thus giving it quorum and allowing it to operate on > it's own. > > digimer > > On 03/22/2013 03:16 AM, emmanuel segura wrote: > >> Hello >> >> If i understand well, you 3 node(3 total votes) and you poweroff 2, 3 - >> 2 = 1(quorum loss) remain less 50% of votes >> >> can you show your config and your log, without it's so hard help you >> >> Thanks >> >> 2013/3/22 Prathyush <[email protected] <mailto:[email protected]> >> **> >> >> 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 >> -- >> /*Regards, >> Prathyush*/ >> > > > -- > Digimer > Papers and Projects: https://alteeve.ca/w/ > What if the cure for cancer is trapped in the mind of a person without > access to education? > > -- > Linux-cluster mailing list > [email protected] > https://www.redhat.com/**mailman/listinfo/linux-cluster<https://www.redhat.com/mailman/listinfo/linux-cluster> >
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