Zombie VMs and overprovisioned VMs are two types of inefficient VMs that can waste resources and increase costs in a Nutanix environment. Zombie VMs are VMs that are powered on but have no activity or utilization for a long period of time. Overprovisioned VMs are VMs that have more resources allocated than they actually need or use. Both types of VMs can be identified by adding predefined views to a report in Prism Central.
A predefined view is a template that defines what data is displayed and how that data is represented in a report. Prism Central provides several predefined views for different purposes, such as capacity planning, performance analysis, anomaly detection, and efficiency optimization. To add a predefined view to a report, go to Operations > Reports > New Report and select the desired view from the list1.
The Zombie VMs List view shows the list of zombie VMs in the environment based on the CPU usage, memory usage, disk IOPS, and network throughput metrics. The view also shows the amount of resources wasted by these VMs and the potential savings that can be achieved by deleting or resizing them2.
The Overprovisioned VMs List view shows the list of overprovisioned VMs in the environment based on the CPU usage, memory usage, disk IOPS, and network throughput metrics. The view also shows the amount of resources wasted by these VMs and the potential savings that can be achieved by resizing them3.
By adding these two views to a report, an administrator can identify inefficient VMs and take appropriate actions to optimize resource utilization and reduce costs.
References: 1: Reports Management - Prism Central Guide 2: Zombie VMs List - Prism Central Guide 3: Overprovisioned VMs List - Prism Central Guide

Load the Virtual SCSI pass-through controller.
The error message shown in the image indicates that Windows 10 setup cannot find any drives to install the OS. This is because the Nutanix AHV hypervisor uses a virtual SCSI pass-through controller to present disks to the VMs, and Windows 10 does not have a built-in driver for this device. Therefore, the administrator needs to load the Nutanix VirtIO driver for the virtual SCSI pass-through controller during the OS installation process. The Nutanix VirtIO driver package contains various drivers that are specifically used by Windows VMs hosted in the Nutanix environment to enhance their stability and performance1. The administrator can download the latest Nutanix VirtIO driver package from the VirtIO downloads page of the Nutanix support portal. The administrator can then follow these steps to load the driver and install the OS2:
On the Windows 10 setup screen, click Load driver.
Insert a USB drive or mount an ISO image that contains the Nutanix VirtIO driver package.
Browse to the location of the driver package and select the folder that matches the OS architecture (32-bit or 64-bit).
Select the vioscsi.inf file and click Next.
Wait for the driver to load and then click Refresh.
Select the disk where you want to install Windows 10 and click Next.
References: 1: VirtIO Driver Versions for Windows 2: Installing Windows on AHV

When a placement policy is enforced, images are only allowed to be deployed on clusters that are part of categories that are associated with the policy. If the desired cluster is not associated with the policy, then the image will not be available for deployment.
https://next.nutanix.com/how-it-works-22/image-management-for-ahv-clusters-and-dealing-with-the-inactive-image-37300

The only option that requires iSCSI initiator configuration in the guest OS to use Volumes is Microsoft Windows Failover Cluster. Volumes is an enterprise-class, software-defined block storage solution that exposes storage resources directly to virtualized guest operating systems or physical hosts using the iSCSI protocol7. To use Volumes, customers need to configure iSCSI initiators on their hosts or guest OSes. However, some applications or services can use native storage adapters instead of iSCSI initiators when running on AHV VMs. These include:
SQL Server Always On Availability Group: This is a high availability and disaster recovery solution for SQL Server databases that uses Windows Server Failover Clustering (WSFC) and Availability Groups (AGs) as its core components. When running on AHV VMs, SQL Server Always On Availability Group can use native storage adapters instead of iSCSI initiators.
Oracle RAC: This is a clustered database system that provides high availability and scalability for Oracle databases. When running on AHV VMs, Oracle RAC can use native storage adapters instead of iSCSI initiators.
Exchange DAG: This is a group of up to 16 mailbox servers that hosts a set of databases and provides automatic database-level recovery from failures that affect individual servers or databases. When running on AHV VMs, Exchange DAG can use native storage adapters instead of iSCSI initiators.