Administrator Guide
Factors That Aect Data Reduction Operation
When a new virtual volume is created, it can use any Data Reduction type supported by the storage container. The preference for the Data
Reduction type on the virtual volume is inuenced by either:
• The VM Storage Prole, if one is established and used
• The default Data Reduction Prole set for the storage center
The following factors aect how Data Reduction options are applied:
• If no VM Storage Policy is chosen, the Data Reduction type defaults to the value selected by the Default Data Reduction Prole.
• Editing an existing storage container’s properties to change the value of the Default Data Reduction Prole does not aect existing
virtual volumes. This change applies only to new volumes created afterward.
• If an existing volume has an enabled feature that is now disabled, the volume itself does not change. In the VM Storage Prole, the
volume would now appear to be noncompliant. To bring the volume back into compliance, you can apply a compliant policy to the
volume.
NOTE: The VM Storage Prole takes precedence when compatible storage exists.
NOTE: VM storage policies are applied only to data and cong VVols and not to memory and swap VVols.
NOTE: When modifying VM storage policies especially for compression and deduplication, apply the VMware administrator
policies to all volumes associated with VM. If these same changes are not applied to all volumes, some portion of the VM could
be compressed while other portions could be uncompressed.
NOTE: The advertised capabilities only apply to VVols datastores and are not supported on legacy VMFS datastores.
NOTE: Any change to a storage container's Data Reduction prole might cause future fast cloned VMs to be created with
mismatched Data Reduction proles for the cong and data VVols. A fast clone VM shares history with the VM from which it was
created. Hence its data VVols inherit the settings of the data VVols of the original VM. There is another side eect of this shared
history — if a user applies a VM Storage Policy to the original VM, the same changes apply to the data VVols of the fast clone
VM and conversely.
NOTE: When applying a VM Storage Policy containing rules for the ScStorageProle capability, the vCenter administrator can
ignore the datastore compatibility warning Datastore does not satisfy required properties.. The VASA provider
overrides the datastore's congured value and applies the user-provided value of ScStorageProle for VVols of the VM.
Expected Behaviors for Data Reduction Scenarios
The settings specied in both the storage container Data Reduction options and in the VMware Storage Prole determine the results of
VM and VVol creation. If the storage container Data Reduction settings conict with the settings in the VM Storage Prole, creation of
VMs and virtual volumes could fail.
The following table describes the expected behavior for new VM creation with the Compression option.
Table 5. Expected Behavior for New VM Creation with Compression
VM Storage Policy = None
Specied
VM Storage Policy =
Compression Enabled
VM Storage Policy =
Compression Disabled
Storage Container Compression
Enabled
Volumes created with Default
Data Reduction prole value
from storage container
Volumes created with
Compression Data Reduction
Prole
Volumes created with the Data
Reduction Prole set to None
Storage Container Compression
Disabled
Volumes created with Default
Data Reduction prole
value from storage container
VM creation fails because user is
trying to set an unsupported
capability
Volumes created with the Data
Reduction Prole set to None
Storage Center Administration 65