Storage policies that you define for virtual machines, capture storage characteristics that virtual machine home files and virtual disks require to run applications within the virtual machine.

When you create a storage policy, you can reference storage capabilities advertised by a storage system. You can also reference user-defined datastore tags.

Although storage policies and storage capabilities have similar semantics, policies describe what users require for their virtual machines, while storage capabilities refer to what the system can offer.

You can create several storage policies to define different types and classes of storage requirements.

Each storage policy is not only a set of constraints that apply simultaneously. A single policy can include alternative sets of subpolicies, or rule-sets, that represent equally acceptable storage requirements.

The virtual machine home files (.vmx, .vmsd, .nvram, .log, and so on) and the virtual disks (.vmdk) can have separate storage policies as shown in the following table.

Table 1. Example Storage Policy for a Virtual Machine

Example Virtual Machine Files

Example for a Storage Policy

Example for a Datastore Compliant with the Storage Policy

windows_2008r2_test.vmx

Storage Policy 2

datastore02, datastore05, datastore10

windows_2008r2_test.vmxf

windows_2008r2_test.log

windows_2008r2_test.nvram

windows_2008r2_test.vmem

windows_2008r2_test.vmsd

windows_2008r2_test.vmdk

Storage Policy 3

datastore05

windows_2008r2_test_1.vmdk

Storage Policy 5

datastore10

When you create, clone, or migrate a virtual machine, you can apply the storage policy to the virtual machine. You can then place the virtual machine to one of the datastores that has capabilities compatible with the policy requirements.

If you select a datastore that does not match the policy, the Policy shows that the virtual machine is using noncompliant storage.