Deduplication and Compression Design Considerations

Consider these guidelines when you configure deduplication and compression in a Virtual SAN cluster.

• Deduplication and compression are available only on all-flash disk groups.
• On-disk format version 3.0 or later is required to support deduplication and compression.
• You must have a valid license to enable deduplication and compression on a cluster.
• You can enable deduplication and compression only if the storage-claiming method is set to manual. You can change the storage-claiming method to automatic after deduplication and compression has been enabled.
• When you enable deduplication and compression on a Virtual SAN cluster, all disk groups participate in data reduction through deduplication and compression.
• Virtual SAN can eliminate duplicate data blocks within each disk group, but not across disk groups.
• Capacity overhead for deduplication and compression is approximately five percent of total raw capacity.
• Policies with 100 percent proportional capacity reservations are always honored. Using these policies can make deduplication and compression less efficient.
• Policies with less than 100 percent proportional capacity are treated as if no proportional capacity reservation was requested. The object remains compliant with the policy, and no events are logged.