Virtual SAN can perform block-level deduplication and compression to save storage space. When you enable deduplication and compression on a Virtual SAN all-flash cluster, redundant data within each disk group is reduced.
Deduplication removes redundant data blocks, whereas compression removes additional redundant data within each data block. These techniques work together to reduce the amount of space required to store the data. Virtual SAN applies deduplication and then compression as it moves data from the cache tier to the capacity tier.
You can enable deduplication and compression as a cluster-wide setting, but they are applied on a disk group basis. When you enable deduplication and compression on a Virtual SAN cluster, redundant data within a particular disk group is reduced to a single copy.
You can enable deduplication and compression when you create a new Virtual SAN all-flash cluster or when you edit an existing Virtual SAN all-flash cluster. For more information about creating and editing Virtual SAN clusters.
When you enable or disable deduplication and compression, Virtual SAN performs a rolling reformat of every disk group on every host. Depending on the data stored on the Virtual SAN datastore, this process might take a long time. It is recommended that you do not perform these operations frequently. If you plan to disable deduplication and compression, you must first verify that enough physical capacity is available to place your data.