In Hitachi Device Manager Storage Navigator for Gx00 series, when opening the edit pool window for HDT pool I can see a check box named "Active Flash", wich does not exist in the same window of Storage Navigator for VSP/HUSVM seies.
I found no explanation in the specific documentation for Gx00 series, only the GUI help says:
"Select the check box if you are using the active flash function. If pool volumes whose drive type is SSD are installed, this check box can be selected. In Thin Image, you cannot change the setting of this function."
What function is it ?
I don't guess it's about using or not SSD pool volumes, because I have not checked that box and they are already properly used for that pool...