Lusca Cache management

[crazyzoar]

Lusca-cache can cache web as well as youtube videos.
we can say that lusca has two features:
1-web caching                2-youtube caching
on my Pfsense box 1TB harddisk is fixed.
i want to give 400gb to web caching and 400gb to youtube cahcing.
My friend says me it is possible if you set your proxy server:-cache management.
what is your view? is it possible? if yes How??????