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.