If your caching I/O filter uses local flash devices, configure a virtual flash resource, also known as VFFS volume. You configure the resource on your ESXi host before activating the filter.

Note: This task is available only in the vSphere Web Client.


To determine whether the virtual flash resource must be enabled, check with your I/O filter vendor.


  1. Navigate to the host.
  2. Click the Configure tab.
  3. Under Virtual Flash, select Virtual Flash Resource Management and click Add Capacity.
  4. From the list of available flash drives, select one or more drives to use for the virtual flash resource and click OK.


The virtual flash resource is created. The Device Backing area lists all the drives that you use for the virtual flash resource.