This clinical trial is studying magnetic resonance spectroscopy imaging in predicting response in patients to vorinostat and temozolomide in patients with recurrent, progressive, or newly diagnosed glioblastoma. Drugs used in chemotherapy, such as temozolomide, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Vorinostat may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Vorinostat may also help temozolomide work better by making tumor cells more sensitive to the drug. Imaging procedures, such as magnetic resonance spectroscopy imaging, may help measure the patient's response to vorinostat and temozolomide and allow doctors to plan better treatment.