[FORM 6-K 21Vianet Group, Inc. Guanjie Building, Southeast 1st Floor Chaoyang District Beijing 100016 The People’s Republic of China (86 10) 8456 2121 Form 20-F x o o o Appointment of Mr. Tim Chen 21Vianet Group, Inc. (“21Vianet” or the “Company”) has appointed Mr. Tim Chen as the Company’s chief str]