VMware Cloud Foundation (VCF) is an integrated software stack where vSAN is the principal storage solution for workload domains. In a multi-tenant environment, ensuring optimal and predictable performance requires granular control over resources. vSAN, through Storage Policy-Based Management (SPBM), allows architects to define specific service levels for different tenant workloads. By creating tiered storage policies (e.g., Gold, Silver, Bronze), an administrator can specify performance characteristics such as IOPS limits, object striping, and read cache reservation. This ensures that high-priority tenant workloads receive the necessary I/O performance and low latency, while preventing any single tenant from monopolizing storage resources, a common issue known as the "noisy neighbor" problem.

A. A single large datastore for all tenants creates a single point of contention, making it impossible to guarantee performance SLAs and exacerbating the "noisy neighbor" problem.

B. Confining all workloads to a single ESXi host is fundamentally against the principles of a scalable, resilient cloud foundation and offers no high availability.

D. Allowing an unlimited number of virtual machines without resource controls leads to severe resource contention and unpredictable performance, which is the opposite of an optimized design.

1. VMware Cloud Foundation 4.5 Design Guide. Section 4.2

vSAN Storage. This section states

"vSAN is the principal storage component of VMware Cloud Foundation for the management domain and for VI workload domains... You use storage policies to define the storage requirements for your virtual machines. These policies determine how the virtual machine storage objects are provisioned and allocated within the datastore to guarantee the required level of service." This directly supports using policies for performance management.

2. VMware vSAN 8.0 U1 Design Guide. Chapter 3

"vSAN Design Considerations

" Page 21. The guide details how vSAN policies control performance and availability. It explains

"Storage Policy Based Management (SPBM) is a key feature of vSAN... SPBM allows for fine-grained control of VM storage services such as performance

availability

and encryption on a per-VM basis." This confirms that SPBM is the intended mechanism for managing performance in shared environments.

3. VMware vSAN Documentation - "Administering VMware vSAN". Section: "Using Storage Policies with vSAN". This documentation details the creation and application of storage policies to manage service levels. It describes settings like "Number of disk stripes per object" and "IOPS limit for object" which are used to tune performance for specific workloads

a critical function for multi-tenancy.