A customer is deploying a SAN cluster of A700 nodes and wants to ensure that the SAN cluster will maintain a quorum in the event of a rack level power failure.
Which two statements are true in this scenario? (Choose two.)
A customer is deploying a SAN cluster of A700 nodes and wants to ensure that the SAN cluster will maintain a quorum in the event of a rack level power failure.
Which two statements are true in this scenario? (Choose two.)
To ensure that a SAN cluster of A700 nodes will maintain a quorum in the event of a rack-level power failure, three racks and six nodes are required. This arrangement ensures that more than half of the nodes remain available even if one entire rack fails. By distributing the nodes across three racks, it guarantees that the loss of one rack (which could still leave two-thirds of the nodes operational) does not compromise the quorum, which requires the majority of nodes to be functional to avoid any configuration conflicts or issues.
A&C...The quorum rule states that to make changes to the configuration in our cluster, we need to have more than half of the nodes available. This prevents configuration conflicts if we lose connectivity between the nodes in our cluster. So, if we have only 2 racks and 4 nodes we could never get more than half of the nodes available if one of those racks power fails. We need 6 nodes separated on 3 racks, so we can have more than half of the nodes available if one of those racks power fails.
B & D are correct. Because there is the possibility of a tie in a cluster that has an even number of nodes, one node has an extra fractional voting weight called epsilon. If the connectivity between two equal portions of a large cluster fails, the group of nodes containing epsilon maintains quorum, assuming that all of the nodes are healthy. For example, the following illustration shows a four-node cluster in which two of the nodes have failed. However, because one of the surviving nodes holds epsilon, the cluster remains in quorum even though there is not a simple majority of healthy nodes. https://docs.netapp.com/us-en/active-iq-unified-manager/health-checker/concept_understand_quorum_and_epsilon.html