How to Expand Data Store Omnirom 5.1.

Hi Everybody ;

İ'm new at forum also custom roms My device is Samsung Galaxy TAB 7 P1000 İ've installed Omnirom,But after installed i've realized that data store on Apps space is 1.5 GB and quickly it became full .the device has 16 GB disk and in this situation free size is about 12 GB on total space

İ can not install and app because of disk size İs there and solution to fix this problem