When trying to configure the write cache, any selection that involves the local HDD of the target device would fail.

Cache on device ram - works
Cache on server - works
Ram with overflow - fails to server
Cache on Device HD - fails to server

Format the WC drive as MBR. This is a requirement of the WC drive.

Problem Cause

The Write cachedisk was formatted at GPT not MBR - which PVS does not support.

Any Write cache mode which involves the Target Device local HDD reverts to server side caching