Assessment tools for sizing virtualized environments are designed to collect performance and configuration data directly from the hypervisor's management plane. Different tools are built to interface with specific platforms, such as VMware vCenter or Microsoft System Center Virtual Machine Manager (SCVMM) for Hyper-V. Therefore, knowing the customer's virtualization platform is the most critical prerequisite for selecting the correct and compatible assessment tool to gather the necessary metrics (CPU, memory, storage I/O, etc.) for an accurate sizing exercise.

A. Public cloud storage usage is part of the overall solution design but does not determine the choice of the on-premises workload assessment tool.

C. Expired support contracts are a business and risk management concern, not a technical prerequisite for the tool that measures current workload performance.

D. The purchasing model (CapEx vs. OpEx) is a financial consideration that influences the final proposal, not the selection of the technical data collection tool.

1. HPE CloudPhysics Documentation: The HPE CloudPhysics platform, a primary assessment tool, utilizes a virtual appliance (Observer) that connects directly to a VMware vCenter Server to collect data. This demonstrates the tool's dependency on a specific hypervisor platform.

Source: HPE CloudPhysics Quick Start Guide, "Deployment Prerequisites" section, consistently notes the requirement for VMware vCenter credentials and network access.

2. HPE Sizer for Private Cloud: While the HPE Sizer tool itself can be used for various platforms, it relies on data imported from performance collection utilities. The choice of the collection utility is dependent on the source environment's hypervisor.

Source: HPE Sizer for Private Cloud Getting Started Guide, Section: "Importing Workload Data," which details importing performance data from tools specific to hypervisor environments like VMware or Hyper-V.

3. Official HPE Solution Brief: Documents describing HPE's assessment services, such as the "HPE Right Mix Advisor," emphasize an initial discovery phase where the existing infrastructure, including the specific virtualization technology, is identified to inform the subsequent data collection and analysis strategy.

Source: HPE Right Mix Advisor Service Data Sheet (a00067633enw), Page 2, "Our approach" section, details the discovery and analysis of the existing IT environment, which inherently includes identifying the hypervisor platform.