SQLSACT (10/31/2012)
Perry Whittle (10/31/2012)
SQLSACT (10/31/2012)
Hi GuysPlease help me understand something the Cluster Quorum and specifically Node and Disk Majority
I understand that if you have an even amount on nodes on your cluster, it's recommended to implement Node and Disk Majority. To avoid the split-brain effect and other undesirables.
My question is, if your disk that you have specified as your Quorum disk goes down, does it take the entire cluster down?
Thanks
Not necessarily, it depends on what other votes are around at the time of failure. More on the new quorum models can be found at this link.
Also, the link above states
Technet online
Can sustain failures of half the nodes (rounding up) if the disk witness remains online. For example, a six node cluster in which the disk witness is online could sustain three node failures.Can sustain failures of half the nodes (rounding up) minus one if the disk witness goes offline or fails. For example, a six node cluster with a failed disk witness could sustain two (3-1=2) node failures.
Thanks
In my case, I have a 2 node 2008 cluster with Node and Disk Majority
I took down the Quorum drive and the entire cluster went down
Normal?
No, as 2 out of 3 votes would have still been available.
Having said that, in your config, removal of the disk witness would not sustain any further node failures.
Re run the cluster validation report and check for errors, also check the event and cluster logs for issues too
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