FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Clark Robert S.
 2. Date of Event Requiring Statement (Month/Day/Year)
04/01/2011		 3. Issuer Name and Ticker or Trading Symbol
QUANTUM CORP /DE/ [QTM]
(Last)
(First)
(Middle)
C/O QUANTUM CORPORATION, 1650 TECHNOLOGY DRIVE, SUITE 800		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
SVP Tape & OEM Products
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

SAN JOSE, CA 95110		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock (1) 103,180
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Non-Qualified Stock Option (2) 04/01/2011(3) 04/01/2017 Common Stock 100,000 $ 2.59 D  
Non-Qualified Stock Option (2) 07/01/2010(4) 07/01/2016 Common Stock 37,500 $ 0.98 D  
Non-Qualified Stock Option (2) 03/01/2010(5) 04/01/2016 Common Stock 14,584 $ 0.77 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Clark Robert S.
C/O QUANTUM CORPORATION
1650 TECHNOLOGY DRIVE, SUITE 800
SAN JOSE, CA 95110		       SVP Tape & OEM Products  

Signatures

/s/ Astrid Becker-Celik, Attorney in Fact for Robert S. Clark 04/08/2011
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Includes 85,916 restricted stock units which will vest as follows: 7,500 will vest on 6/1/11, 21,750 will vest on 7/1/11, 20,000 will vest on each of 7/1/12 and 7/1/13, and 8,333 will vest on each of 4/1/12 and 4/1/13.
(2) Right to buy under Rule 16b(3) Plan.
(3) Includes 75,000 stock options that are not vested and will vest monthly at the rate of 1/48 of the original grant amount of 100,000 through 4/1/2014.
(4) Stock options will vest as follows: 25,000 will vest on 7/1/2011 and 12,500 will vest on 7/1/2012.
(5) Includes 11,980 stock options that are not vested and will vest monthly at the rate of 1/48 of the original grant amount of 25,000 through 3/1/2013.

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