You can enable or disable the WAFL external cache functionality for a storage system that has a caching module installed (Performance Acceleration Module, Flash Cache module, or Flash Cache 2 module). You should verify that the WAFL external cache functionality is enabled after you install a caching module.
The flexscale.enable option enables or disables the WAFL external cache functionality. If your storage system does not have a caching module installed, the flexscale.enable option enables or disables the Predictive Cache Statistics (PCS). PCS is supported on platforms that support caching modules.
WAFL external cache does not require a separate license if your system is running Data ONTAP 8.1 or later. PCS does not require a license.