Running out of free space in raid1 array

[NHRA-NO-2]

I have a newbie question. I am running 0.7.2 w/ two 2TB drives in mirror software raid 1 array. The status reports about 1.6TB usable, but only 1.06 free space. I have been deleting old outdated files, and by checking each main folder they add up to 940.94GB total. In both the FreeNAS gui shows only 1.06GB free and windows show about 1GB free. What do I need to do to get FreeNAS & windows to show the correct amount of disc free space?

 

[ProtoSD]

You should ask your question in the FreeNAS .7 forums (link at top of page in titlebar), these forums are for 8.x