Dell PowerEdge RAID Controller 9 User’s Guide H330, H730, and H830

The controller preserves the dirty cache from a virtual disk if the virtual disk becomes offline or is deleted because of missing physical disks. This preserved dirty cache is called pinned cache and is preserved until you import the virtual disk or discard the cache.

Use the BIOS Configuration Utility (<Ctrl> <R>) to select whether to import the virtual disk or discard the preserved cache. In the VD Mgmt menu, select Manage Preserved Cache and follow the steps on the screen.