You can enable View Storage Accelerator on pools that contain instant clones and on pools that contain full-clone virtual machines. This feature uses the Content Based Read Cache (CBRC) feature in ESXi hosts.

CBRC uses ESXi host memory to cache virtual machine disk data, reduce IOPS, and improve performance during boot storms, when many machines start up or run anti-virus scans at once. By reducing the number of IOPS during boot storms, View Storage Accelerator lowers the demand on the storage array, which lets you use less storage to support your Horizon deployment. The feature is also beneficial when administrators or users load applications or data frequently.

When a virtual machine is created, Horizon indexes the contents of each virtual disk file. The indexes are stored in a virtual machine digest file. At runtime, the ESXi host reads the digest files and caches common blocks of data in memory. To keep the ESXi host cache up to date, Horizon regenerates the digest file at regular intervals. You can modify the regeneration interval.

Native NFS snapshot technology (VAAI) and Vvols are not supported in pools that are enabled for View Storage Accelerator. vSphere VM Encryption is also not supported with View Storage Accelerator.

To enable the View Storage Accelerator feature, you must enable it globally and then enable it for individual desktop pools. For details on how to enable or disable View Storage Accelerator globally, see the Horizon Installation document.

After View Storage Accelerator is enabled globally, you can enable or disable it for individual full-clone desktop pools. For instant-clone desktop pools, View Storage Accelerator is only needed for replica VMs and is enabled automatically for individual pools. It cannot be turned off on a pool level. To disable, you must disable View Storage Accelerator globally, and this step will also disable the feature for full clone pools.

View Storage Accelerator is enabled for a full-clone pool by default. The feature can be disabled or enabled when you create or edit a pool. The best approach is to enable this feature when you first create a desktop pool.


  1. In Horizon Console, display the Advanced Storage Options tab in the pool creation wizard.
    Option Description
    New desktop pool (recommended) Start the Add Pool wizard to begin creating an automated desktop pool. Follow the wizard configuration prompts until you reach the Advanced Storage Options page.
    Existing desktop pool Select the existing pool, click Edit, and click the Advanced Storage Options tab.

    If you modify View Storage Accelerator settings for an existing desktop pool, the changes do not take effect until the virtual machines in the desktop pool are powered off.

  2. To enable View Storage Accelerator for the pool, make sure that the Use View Storage Accelerator check box is selected.
    This setting is selected by default. To disable the setting, uncheck the Use View Storage Accelerator box. You cannot select a disk type. View Storage Accelerator is performed on the whole virtual machine.
  3. (Optional) In the Regenerate storage accelerator after text box, specify the interval, in days, after which the regeneration for View Storage Accelerator digest files take place.
    The default regeneration interval is seven days.

What to do next

You can configure blackout days and times during which disk space reclamation and View Storage Accelerator regeneration do not take place. See Set Storage Accelerator and Space Reclamation Blackout Times.