X0304 4 2011-09-01 0 0000709283 QUANTUM CORP /DE/ QTM 0001077821 MARENGI JOSEPH A C/O QUANTUM CORPORATION 1650 TECHNOLOGY DRIVE, SUITE 800 SAN JOSE CA 95110 1 0 0 0 Common Stock 2011-09-01 4 A 0 50000 0 A 141354 D Restricted Stock Units will vest over one (1) year as follows: 25% will vest on each of 12/1/11, 3/1/12, 6/1/12 and the date of Quantum Corporation's 2012 Annual Shareholder Meeting. /s/ Astrid Becker-Celik, Attorney in Fact for Joseph A. Marengi 2011-09-02