Enable Deduplication and Compression on an Existing vSAN Cluster

You can enable deduplication and compression by editing configuration parameters on an existing all-flash vSAN cluster.

To enable on a vSAN Original Storage Architecture cluster:

1. Navigate to the vSAN cluster.
2. Click the Configure tab.
3. Under vSAN, select Services
   1. Click to edit Space Efficiency.
   2. Select a space efficiency option: Deduplication and compression, or Compression only.
   3. (Optional) Select Allow Reduced Redundancy. If needed, vSAN reduces the protection level of your VMs while enabling Deduplication and Compression. For more details, see Reduce VM Redundancy for vSAN Cluster.
4. Click Apply to save your configuration changes.

To enable on a vSAN Express Storage Architecture cluster:

1. Navigate to the cluster.
2. Click the Configure tab.
3. Under vSAN, select Services.
4. Under Data Services, click EDIT.
   1. Under Encryption, enable data-at-rest encryption by using the toggle button.
      Note: You cannot change this setting after claiming disks.
   2. Enable data-in-transit encryption by using the Data-In-Transit encryption toggle button, and specify the rekey interval.
   3. (Optional) Select Allow Reduced Redundancy. If needed, vSAN reduces the protection level of your VMs while enabling Deduplication and Compression. For more details, see Reduce VM Redundancy for vSAN Cluster.
5. Click Apply to save your configuration changes.

While enabling deduplication and compression, vSAN updates the on-disk format of each disk group of the cluster. To accomplish this change, vSAN evacuates data from the disk group, removes the disk group, and recreates it with a new format that supports deduplication and compression.

The enablement operation does not require virtual machine migration or DRS. The time required for this operation depends on the number of hosts in the cluster and amount of data. You can monitor the progress on the Tasks and Events tab.