All NCS-Core Test Inside Nutanix Questions

The most straightforward approach for increasing security by disabling password authentication and moving to key-based SSH on a Nutanix cluster involves:

• C. Enable Cluster Lockdown and provide an RSA key: Cluster Lockdown mode restricts management access to the cluster, ensuring that only key-based SSH authentication is used to access the CVM and AHV hosts, enhancing security by eliminating the use of passwords.

References:

• Nutanix Bible (https://www.nutanixbible.com), particularly sections discussing secure access and authentication methods.
• Nutanix University: NCS-Core 6.8 Training (https://university.nutanix.com), where security features like Cluster Lockdown are covered.

In a Nutanix cluster, when a Controller Virtual Machine (CVM) fails, the iSCSI targets for the volume groups managed by that CVM are not left inoperable. Instead, the volume group's iSCSI targets (vDisks) are automatically redirected to another operational CVM in the cluster. This failover mechanism ensures that there is no interruption in service or data availability. The redirection is seamless and does not require manual intervention, allowing for continuous access to the volume group by the SQL cluster.

References:

• Nutanix Bible: Data Protection and High Availability
• Nutanix University: Resiliency and Disaster Recovery

To increase the Redundancy Factor (RF) from 2 to 3, at least five nodes are required for the cluster to function correctly with RF3, as each data block needs to be replicated to three different nodes. However, the optimal solution that offers both the necessary node count and sufficient storage overhead is:

• Six Compute Nodes with 25% available disk space: This configuration ensures that there are enough nodes to support RF3 while maintaining adequate storage capacity for redundancy without overutilization.

References:

• Nutanix Bible (https://www.nutanixbible.com), particularly the sections on redundancy factors and node requirements.
• Nutanix University: NCS-Core 6.8 Training (https://university.nutanix.com), focusing on cluster scaling and redundancy considerations.

To ensure additional resiliency in a 20-node ESXi deployment capable of surviving the concurrent loss of two nodes, the consultant should configure the system with a storage reservation and HA (High Availability) admission control each set to 5%, combined with a cluster redundancy factor (RF) of 3. RF3 provides the capability to tolerate the failure of up to two nodes without data loss, thus enhancing the cluster's resilience. This configuration is optimal for maintaining cluster availability and integrity during multiple node failures.References: Nutanix Bible, Nutanix University