Increasing the number of vCPUs from 2 to 4 can indeed reduce login times by providing more processing power to handle the login requests. However, this action will have two main impacts on the cluster:
A). Increase CPU utilization%: By increasing the number of vCPUs, you are effectively increasing the demand for CPU resources. This will result in a higher percentage of the CPU being utilized.
B). Increase CPU ready%: CPU Ready is a measure of the amount of time a virtual machine is ready to run against the pCPU, but is waiting to be scheduled on the physical CPU. By increasing the number of vCPUs, you are increasing the number of virtual machines that are ready to run, which can increase the CPU Ready percentage.
Increasing the vCPU count does not directly affect memory utilization, so options C and D are not correct.
References:
* The conclusions above are based on general virtualization principles covered in resources like the Nutanix Bible (https://www.nutanixbible.com/) and the Nutanix University training materials for NCS- Core certification (https://university.nutanix.com/). These sources explain the impact of CPU allocation and utilization in detail, particularly in the context of cluster performance and virtual desktop infrastructure.
* Additionally, practical insights into these dynamics are discussed in various video tutorials from the Nutanix official YouTube playlist for NCS-Core learning (https://www.youtube.com/playlist?
list=PLAHgaS9IrJecs_AcQT3Y7vSsKT2mjz3Iu), which provide visual and step-by-step breakdowns of how CPU resources are managed in a Nutanix environment.

Before arriving onsite, the consultant should set up the SMTP server to allow emails from both the Cluster Virtual IP Address (VIP) and the Controller Virtual Machine (CVM) IP addresses. This setup ensures that Prism can successfully send email notifications through the customer's mail server about any errors or notifications generated by the Nutanix environment, as both the Cluster VIP and CVM IPs are sources from which Prism sends alerts.References: Nutanix Bible, Nutanix University NCS-Core 6.8 learning materials

The customer is experiencing VM performance issues characterized by excessive read/write I/Os on CVMs and excessive motion of VMs due to the Distributed Resource Scheduler (DRS) in an ESXi-based Nutanix cluster. This is likely caused by the DRS migration threshold being set to Aggressive, which leads to frequent rebalancing of workloads across the cluster, causing high I/O and VM motion. Adjusting this setting to a less aggressive level can help reduce unnecessary VM motions and stabilize performance.References: Nutanix Bible, Nutanix University NCS-Core 6.8 learning materials

Ref: https://www.vvlsystems.com/wp-content/uploads/2016/11/BP-2009_Metro_Availability.pdf