6.0.1

Understanding Virtual Machine Storage Policies
Virtual machine storage policies capture storage characteristics that virtual machine home les and virtual
disks require to run applications within the virtual machine. You can create several storage policies to dene
the 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 are datastore-specic and represent equally acceptable
storage requirements. If you use vSphere APIs for I/O Filtering, the storage policy can include rules that are
common for all storage types. The policy can contain only common rules, or only datastore-specic rule sets,
or both.
When you create, clone, or migrate a virtual machine, you can apply the storage policy to the virtual
machine. You can place the virtual machine in one of the datastores that matches the policy requirements. To
match the policy requirement, the datastore must satisfy the following guidelines:
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When I/O Filtering and common rules are not available, the datastore must satisfy all rules in at least
one of the datastore specic rule sets.
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With common rules enabled, the datastore must satisfy all common rules and all rules in at least one of
the rule sets.
The virtual machine home les (.vmx, .vmsd, .nvram, .log, and so on) and the virtual disks (.vmdk) can have
separate storage policies.
Table 20‑2. 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
Storage Policies and Rules
Rules that you include in a storage policy can be based on storage-specic data services and tags, or the
rules can be common.
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Common Rules on page 229
Common rules are based on data services that are generic for all types of storage and do not depend
on a datastore. These additional services become available in the VM Storage Policies interface when
you install third-party I/O lters developed through vSphere APIs for I/O Filtering. You can reference
these data services in a VM storage policy.
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Rules Based on Storage-Specic Data Services on page 229
These rules are based on data services that storage entities such as Virtual SAN and Virtual Volumes
advertise.
vSphere Storage
228 VMware, Inc.