Ownership Submission

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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3235-0104

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(Print or Type Responses)

1. Name and Address of Reporting Person ^*

GACEK JON W

2. Date of Event Requiring Statement (Month/Day/Year)
08/22/2006

3. Issuer Name and Ticker or Trading Symbol
QUANTUM CORP /DE/ [DSS]

(Last)

(First)

(Middle)

C/O QUANTUM CORPORATION, 1650 TECHNOLOGY DRIVE, SUITE 700

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

_____ Director	_____ 10% Owner
__X__ Officer (give title below)	_____ Other (specify below)
EVP & Chief Financial Officer

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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

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)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Non-Qualified Stock Option	08/22/2006⁽¹⁾	05/15/2007	DSS Common Stock	179,268	$ 1.41	D
Non-Qualified Stock Option	08/22/2006⁽¹⁾	08/14/2012	DSS Common Stock	59,756	$ 0.88	D
Non-Qualified Stock Option	08/22/2006⁽¹⁾	02/12/2013	DSS Common Stock	29,878	$ 1	D
Non-Qualified Stock Option	08/22/2006⁽¹⁾	08/13/2013	DSS Common Stock	179,268	$ 1.71	D
Non-Qualified Stock Option	08/22/2006⁽¹⁾	08/13/2014	DSS Common Stock	119,512	$ 1.52	D
Non-Qualified Stock Option	08/22/2006⁽¹⁾	08/22/2010	DSS Common Stock	239,024	$ 1.46	D
Non-Qualified Stock Option ⁽²⁾	09/01/2006⁽³⁾	09/01/2013	DSS Common Stock	1,000,000	$ 2.15	D
Restricted Stock Units	⁽⁴⁾	⁽⁴⁾	DSS Common Stock	100,000	$ ⁽⁶⁾	D
Restricted Stock Units	⁽⁵⁾	⁽⁵⁾	DSS Common Stock	200,000	$ ⁽⁶⁾	D

Reporting Owners

Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
GACEK JON W C/O QUANTUM CORPORATION 1650 TECHNOLOGY DRIVE, SUITE 700 SAN JOSE, CA 95110			EVP & Chief Financial Officer

Signatures

/s/ Zoey Armstrong, by Zoey Armstrong, Attorney in Fact for Jon C. Gacek		09/05/2006
^**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)	These options were granted under the 1999 Stock Incentive Plan of Advanced Digital Information Corporation ("ADIC"), which were assumed by Quantum Corporation ("Quantum") on August 22, 2006, pursuant to the Agreement and Plan of Merger (the "Merger Agreement") between ADIC and Quantum. The options were exchanged for options to purchase Quantum common stock, at an exchange ratio of 5.9756 per share, and are immediately vested.
(2)	'Right to Buy' granted under 16b-3 Plan.
(3)	Stock Options will vest over a period of three (3) years, as follows: the first 33% will vest on September 1, 2007 with the remainder vesting in equal annual installments over the following two (2) years.
(4)	Restricted Stock Units will vest over a period of two (2) years, as follows: the first 50% will vest on September 1, 2007 and the remaining 50% on September 1, 2008.
(5)	Restricted Stock Units will vest over a period of three (3) years, as follows: the first 33% will vest on September 1, 2007 with the remainder vesting in equal annual installments over the following two (2) years.
(6)	Restricted Stock Units convert to shares of Common Stock on a 1-for-1 basis.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

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