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, Section 17(a) of the Public Utility Holding Company Act of 1935 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 *   EMC CORP 2. Date of Event Requiring Statement (Month/Day/Year) 12/17/2010 3. Issuer Name and Ticker or Trading Symbol Isilon Systems, Inc. [ISLN] (Last) (First) (Middle) 176 SOUTH STREET 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) 5. If Amendment, Date Original Filed(Month/Day/Year) (Street) HOPKINTON, MA 01748 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, par value $0.00001 per share 64,268,239 (1) (2) (4) I See Footnote (3)

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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

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
EMC CORP 176 SOUTH STREET HOPKINTON, MA 01748	Â	  X	Â	Â

Signatures

/s/ Paul T. Dacier, Executive Vice President and General Counsel		12/21/2010
**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)	On November 14, 2010, EMC Corporation, a Massachusetts corporation ("EMC"), Electron Merger Corporation, a Delaware corporation and a wholly-owned subsidiary of EMC ("Purchaser"), and Isilon Systems, Inc., a Delaware corporation (the "Company"), entered into an Agreement and Plan of Merger (the "Merger Agreement"). As contemplated by the terms of the Merger Agreement, Purchaser commenced, on November 19, 2010, a cash tender offer (the "Offer") to purchase all outstanding shares (the "Shares") of common stock, par value $0.00001 per Share, of the Company, at a price of $33.85 per Share, net to the seller in cash, and subject to the terms and conditions set forth in the Offer to Purchase, dated November 19, 2010, as amended, included as an exhibit to the Tender Offer Statement on Schedule TO filed by EMC and Purchaser with the Securities and Exchange Commission (the "SEC") on November 19, 2010.
(2)	The Offer expired at 12:00 midnight, New York City time, on Friday, December 17, 2010. An aggregate of 63,988,828 Shares were validly tendered and not withdrawn (including certain shares tendered under guaranteed delivery procedures), representing approximately 95.5% of the Company's outstanding common stock. On December 17, 2010, Purchaser accepted for payment all validly tendered and not withdrawn Shares. Prior to the commencement of the Offer EMC, acquired 279,411 Shares through ordinary brokerage transactions at prevailing market prices.
(3)	Purchaser was a direct, wholly owned subsidiary of EMC and was the owner of the Shares purchased in the Offer. Pursuant to the terms of the Merger Agreement, on December 21, 2010 Purchaser merged with and into the Company (the "Merger") and each share of common stock, par value $0.01 per share, of Purchaser that was outstanding immediately prior to the Merger was converted into one share of common stock, par value $0.01 per share, of the Company, as the surviving corporation. As a result of the Merger, Purchaser's corporate existence ceased.
(4)	On December 21, 2010, the Company filed a Form 15 with the SEC to terminate the registration of its common stock under Section 12 of the Securities Exchange Act of 1934, as amended.

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