SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934*

Data Domain, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value

(Title of Class of Securities)

23767P109

(CUSIP Number)

June 30, 2009

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

[ ] Rule 13d-1(b)

[X] Rule 13d-1(c)

[ ] Rule 13d-1(d)


* The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).


----------------------------
CUSIP No. 23767P109
--------------------------------------------------------------------------------

 1 NAME OF REPORTING PERSONS

 Mason Capital Management LLC, in its capacity as investment manager
 for certain investment funds and managed accounts
--------------------------------------------------------------------------------
 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
 (See Instructions) (a) [ ]
 (b) [X]
--------------------------------------------------------------------------------
 3 SEC USE ONLY
--------------------------------------------------------------------------------
 4 CITIZENSHIP OR PLACE OF ORGANIZATION

 Delaware
--------------------------------------------------------------------------------
 NUMBER OF 5 SOLE VOTING POWER
 SHARES
 BENEFICIALLY 3,246,919
 OWNED BY -----------------------------------------------------------
 EACH 6 SHARED VOTING POWER
 REPORTING
 PERSON WITH -0-
 -----------------------------------------------------------
 7 SOLE DISPOSITIVE POWER

 3,246,919
 -----------------------------------------------------------
 8 SHARED DISPOSITIVE POWER

 -0-
--------------------------------------------------------------------------------
 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

 3,246,919 shares of Common Stock
--------------------------------------------------------------------------------
 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES [ ]

 CERTAIN SHARES (See Instructions)
--------------------------------------------------------------------------------
 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

 5.2%
--------------------------------------------------------------------------------
 12 TYPE OF REPORTING PERSON (See Instructions)

 OO
--------------------------------------------------------------------------------

 2


SCHEDULE 13G

ITEM 1(a). NAME OF ISSUER:

Data Domain, Inc.

ITEM 1(b). ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES: 2421 Mission College Blvd.

Santa Clara, CA 95054

ITEM 2(a) NAME OF PERSON FILING; CITIZENSHIP:
and (c). -----------------------------------

This Schedule is being filed by Mason Capital Management LLC ("Mason Management"), a Delaware limited liability company, with respect to shares of Common Stock directly owned by Mason Capital, LP ("Mason Capital LP"), a Delaware limited partnership; Mason Capital, Ltd. ("Mason Capital Ltd"), a corporation organized under the laws of the Cayman Islands; and certain other funds and accounts (the "Managed Accounts").

Mason Management is the investment manager of each of Mason Capital LP, Mason Capital Ltd and the Managed Accounts, and Mason Management may be deemed to have beneficial ownership over the shares of Common Stock reported in this Schedule by virtue of the authority granted to Mason Management by Mason Capital LP, Mason Capital Ltd and the Managed Accounts to vote and dispose of such shares.

ITEM 2(b). ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:

The address of the principal business office of Mason Management is:

110 East 59th Street New York, New York 10022

ITEM 2(d). TITLE OF CLASS OF SECURITIES:

Common Stock, $0.0001 par value

ITEM 2(e). CUSIP NUMBER:

23767P109

ITEM 3. IF THIS STATEMENT IS FILED PURSUANT TO ss.ss. 240.13d-1(b), OR

240.13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:

Not applicable.

3

ITEM 4. OWNERSHIP.

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a) Amount beneficially owned: 3,246,919.

(b) Percent of class: 5.2%.

(c) Number of shares as to which such person has:

(i) Sole power to vote or direct the vote 3,246,919.

(ii) Shared power to vote or direct the vote -0-.

(iii) Sole power to dispose or direct the disposition of 3,246,919.

(iv) Shared power to dispose or direct the disposition of -0-.

The number of shares beneficially owned and the percentage of outstanding shares represented thereby for Mason Management have been computed in accordance with Rule 13d-3 under the Securities Exchange Act of 1934, as amended. The percentage of ownership described above is based on 62,872,045 shares of Common Stock outstanding as of June 5, 2009, as reported in the issuer's proxy statement filed with the Securities and Exchange Commission on June 10, 2009.

ITEM 5. OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

Not applicable

ITEM 6. OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER
PERSON.

The right to receive dividends from, or the proceeds from the sale of, all shares of Common Stock reported in this statement as beneficially owned by Mason Management is held by Mason Capital LP, Mason Capital Ltd or the Managed Accounts, as the case may be, all of which are the advisory clients of Mason Management. To the knowledge of Mason Management, none of these advisory clients holds such right with respect to more than five percent of the outstanding Common Stock. Mason Management itself disclaims beneficial ownership of all shares of Common Stock reported in this statement pursuant to Rule 13d-4 under the Securities Exchange Act of 1934, as amended.

4

ITEM 7. IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH

ACQUIRED THE SECURITIES BEING REPORTED ON BY THE PARENT
HOLDING COMPANY OR CONTROL PERSON.

Not applicable.

ITEM 8. IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.

Not applicable.

ITEM 9. NOTICE OF DISSOLUTION OF GROUP.

Not applicable.

ITEM 10. CERTIFICATION.

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

SIGNATURE

After reasonable inquiry and to the best of the knowledge and belief of the undersigned Reporting Person, the undersigned Reporting Person certifies that the information set forth in this statement with respect to it is true, complete and correct.

Dated: July 10, 2009

MASON CAPITAL MANAGEMENT LLC,

By: /s/ John Grizzetti
 ----------------------------
 John Grizzetti
 Chief Financial Officer

5
Data Domain (MM) (NASDAQ:DDUP)
Gráfico Histórico do Ativo
De Mai 2024 até Jun 2024 Click aqui para mais gráficos Data Domain (MM).
Data Domain (MM) (NASDAQ:DDUP)
Gráfico Histórico do Ativo
De Jun 2023 até Jun 2024 Click aqui para mais gráficos Data Domain (MM).