Explanation: Automated live migration is a feature of Nutanix that allows the cluster to automatically move VMs from one host to another without any downtime, in order to optimize the performance and availability of the cluster. According to the Nutanix documentation1, automated live migration can occur in the following scenarios:
Cluster resource hotspot: When a host or a group of hosts experience high resource utilization, such as CPU, memory, or network, the cluster can automatically migrate some VMs to other hosts with lower utilization, in order to balance the load and avoid performance degradation. AOS upgrade: When upgrading the Nutanix software (AOS), the cluster can automatically migrate the VMs from the host that is being upgraded to another host in the same availability zone, in order to maintain the VM availability and minimize the impact of the upgrade process. AHV host maintenance mode: When putting an AHV host into maintenance mode, the cluster can automatically migrate all the VMs from that host to another host in the same availability zone, in order to prepare the host for maintenance operations such as hardware replacement or firmware update.

Explanation: One of the possible reasons for a cluster to transition out of NearSync is insufficient network bandwidth between the source and target clusters. NearSync requires a minimum network bandwidth of 10 Mbps per VM for replication3. If the network bandwidth is lower than the required amount, the replication of recovery points may take longer than the configured RPO, resulting in an Out of NearSync condition. To address this issue, you can increase the network bandwidth between the clusters or reduce the number of VMs protected by NearSync4.
References: 1: Stargate - Nutanix Bible 2: Nutanix Cluster Architecture Overview - Nutanix Bible 3: NearSync Disaster Recovery (RPO <= 15 minutes) - Nutanix Support & Insights 4: Transitioning in and out of NearSync - Nutanix Support & Insights

Explanation: To periodically send information about cluster efficiency via email to a set of users, the administrator can follow these steps:
Create a report in Prism Central that contains the relevant information about cluster efficiency. Add a schedule to the report to generate and send the report via email to the set of users at a specified frequency.
This will ensure that the users receive regular updates about the cluster efficiency without the need for manual intervention.

Explanation: According to the Nutanix Community1, users can authenticate using their Active Directory credentials when Active Directory support is enabled for Prism Central. To enable Active Directory support, you need to configure Role Mapping12, which defines how Active Directory groups map to Prism Central roles.

Explanation: When a node with Erasure Coding fails, the cluster will automatically rebuild the missing data using replication factor (RF) 2 or 3, depending on the cluster configuration. This means that the data that was previously stored using Erasure Coding will now be stored using full copies, which may increase the amount of data stored in the SSD tier1.

Explanation: According to the Troubleshoot high memory issues on Azure virtual machines web search result2, one of the common factors in a low memory situation is over-provisioning memory for a VM. Over-provisioning memory can cause memory pressure, which leads to swapping and degraded performance. Therefore, to fix this issue, the administrator should reduce the amount of memory assigned to the VM, based on the average hardware requirements for that operating system and application load.

Explanation: The node is automatically re-imaged using the software currently running in the cluster. This is because Nutanix supports a feature called Auto Re-Image that allows adding nodes with different AOS versions to an existing cluster without manual intervention. The Auto Re-Image feature detects the AOS version mismatch and automatically downloads and installs the same AOS version as the cluster on the new node. This ensures that the cluster remains in a consistent state and avoids any compatibility issues.

Explanation: According to the web search results, two steps that should be taken to prepare for relocating an AHV cluster to a new datacenter during a maintenance window are:
Shut down all user VMs in the cluster: This step is necessary to ensure that there is no data loss or corruption during the relocation process. The user VMs can be shut down either individually or in bulk by using the Prism Element web console or the acli command-line interface1.
Stop all Nutanix Files clusters: If the AHV cluster hosts any Nutanix Files clusters, they should be stopped before relocating the cluster. Nutanix Files clusters are composed of one or more virtual machines that provide file services to clients. Stopping a Nutanix Files cluster will stop all the file server VMs and release the resources they consume2. The Nutanix Files clusters can be stopped by using the Prism Element web console or the ncli command-line interface3.