Storage Policy Based Management (SPBM) is the vSphere framework that enables administrators to define storage requirements for virtual machines on a per-VM or per-virtual disk basis. Administrators can create tags and assign them to datastores to categorize them (e.g., by performance tier, data protection level). They then create a VM storage policy that includes rules referencing these tags. When this policy is applied to a virtual machine or its disks, vSphere ensures that the VMDKs are placed only on datastores that have the matching tag, thereby achieving tag-based placement.

B. Storage I/O Control: This feature prioritizes storage I/O for virtual machines during periods of contention on a datastore; it does not control initial placement.

C. vSphere Storage APIs for Storage Awareness (VASA): VASA is an API that allows storage arrays to communicate their capabilities to vCenter. SPBM uses this information, but SPBM is the management framework that creates the tag-based rules.

D. vSphere Distributed Resource Scheduler (DRS): DRS balances compute workloads (CPU and memory) across hosts in a cluster. It is not used for storage placement based on tags.

1. VMware vSphere 8.0 Documentation

"vSphere Storage

" Chapter 6: Working with VM Storage Policies

Section: Create a VM Storage Policy for Tag-Based Placement.

This section explicitly states: "You can define a VM storage policy that is based on storage-specific tags. When you use this type of policy for a virtual machine

the virtual machine is placed on a datastore that has the specified tag." This directly confirms that SPBM is the mechanism for tag-based placement.

2. VMware vSphere 8.0 Documentation

"vSphere Storage

" Chapter 1: vSphere Storage Fundamentals

Section: VM Storage Policies.

This section describes the role of SPBM: "VM storage policies capture storage requirements for your virtual machines... After you define the policy

you can apply it to the virtual disks... vCenter Server places the virtual machine on a datastore that satisfies the requirements of the assigned policy."

3. VMware vSphere 8.0 Documentation

"vSphere Resource Management

" Chapter 10: Managing Storage Resources

Section: Storage I/O Control.

This reference clarifies the function of SIOC: "When you enable Storage I/O Control on a datastore

ESXi begins to monitor the I/O load of the virtual machines... When latency exceeds the threshold

the datastore is considered congested and Storage I/O Control allocates I/O resources to virtual machines according to their shares." This shows its purpose is I/O management

not placement.