Administrator Guide

Factors That Aect 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 inuenced by either:
• The VM Storage Prole, if one is established and used
• The default Data Reduction Prole set for the storage center
The following factors aect 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 Prole.
• Editing an existing storage container’s properties to change the value of the Default Data Reduction Prole does not aect 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 Prole, 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 Prole takes precedence when compatible storage exists.
NOTE: VM storage policies are applied only to data and cong 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 prole might cause future fast cloned VMs to be created with
mismatched Data Reduction proles for the cong 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 eect 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 ScStorageProle capability, the vCenter administrator can
ignore the datastore compatibility warning Datastore does not satisfy required properties.. The VASA provider
overrides the datastore's congured value and applies the user-provided value of ScStorageProle for VVols of the VM.
Expected Behaviors for Data Reduction Scenarios
The settings specied in both the storage container Data Reduction options and in the VMware Storage Prole determine the results of
VM and VVol creation. If the storage container Data Reduction settings conict with the settings in the VM Storage Prole, 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
Specied
VM Storage Policy =
Compression Enabled
VM Storage Policy =
Compression Disabled
Storage Container Compression
Enabled
Volumes created with Default
Data Reduction prole value
from storage container
Volumes created with
Compression Data Reduction
Prole
Volumes created with the Data
Reduction Prole set to None
Storage Container Compression
Disabled
Volumes created with Default
Data Reduction prole
value from storage container
VM creation fails because user is
trying to set an unsupported
capability
Volumes created with the Data
Reduction Prole set to None
Storage Center Administration 65