##### Table of Contents



UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
 Washington, D.C. 20549
 FORM 10-K/A(AMENDMENT NO. 1)
 (Mark One)
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    ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
EXCHANGE ACT OF 1934
 For the fiscal year ended December 31, 2006
 OR
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    TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
 For the transition period from  to
 Commission File Number 001-33196
 Isilon Systems, Inc.
 (Exact name of registrant as specified in its charter)
 Delaware
(State or other jurisdiction of 
incorporation or organization)
    
    91-2101027
(IRS Employer
Identification No.)
 3101 Western Ave
Seattle, WA 98121
(Address of principal executive offices) (Zip code)
 Registrants telephone number, including area code:
206-315-7500
 
 Securities registered pursuant to Section 12(b) of the Act: None
 Securities registered pursuant to Section 12(g) of the Act: Common Stock, par value $.00001 per share
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TABLE OF CONTENTS  EXPLANATORY NOTESIGNATURESINDEX TO EXHIBITSEXHIBIT 31.1EXHIBIT 31.2EXHIBIT 32.1EXHIBIT 32.2    Table of Contents  ISILON SYSTEMS, INC.
 
 EXPLANATORY NOTE




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##### Table of Contents



SIGNATURES
  ISILON SYSTEMS, INC.By:
    /s/       Steven GoldmanSteven GoldmanPresident, Chief Executive Officer and Director .
 Signature
    
    Title
    
    Date/s/ Steven Goldman
Steven Goldman
    
    President, Chief Executive Officer
and Director
(Principal Executive Officer)
    
    August 8, 2007/s/ Stuart W. Fuhlendorf
Stuart W. Fuhlendorf
    
    Chief Financial Officer and
Vice President of Finance
(Principal Accounting and
Financial Officer)
    
    August 8, 2007




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INDEX TO EXHIBITS
 Incorporation by Reference HereinExhibitNumber
    
    Description
    
    Form
    
    Date3.1
    
    Amended and Restated Certificate of Incorporation of the
registrant.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 20063.2
    
    Amended and Restated Bylaws of the registrant.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 20064.1
    
    Form of registrants common stock certificate.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 24, 20064.2
    
    Fourth Amended and Restated Investors Rights Agreement
between the registrant and certain of its security
holders dated July 19, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.1
    
    Form of Indemnification Agreement.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.2
    
    Amended and Restated 2001 Stock Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.3
    
    Form of Stock Option Agreement under the Amended and
Restated 2001 Stock Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.4
    
    2006 Equity Incentive Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 24, 200610.5
    
    Form of Stock Option Agreement under the 2006 Equity
Incentive Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 24, 200610.6
    
    2006 Employee Stock Purchase Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 24, 200610.7
    
    Form of Subscription Agreement under the 2006 Employee
Stock Purchase Plan.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 24, 200610.8
    
    Offer Letter with Steven Goldman dated July 17, 2003.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.9
    
    Offer Letter with Eric J. Scollard dated October 4, 2002.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.10
    
    Offer Letter with Mark L. Schrandt dated October 3, 2003.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.11
    
    Offer Letter with Brett G. Goodwin dated March 10, 2002.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.12
    
    Offer Letter with John W. Briant dated September 29,
2004.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.13
    
    Offer Letter with Stuart W. Fuhlendorf dated March 29,
2004.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.14
    
    Offer Letter with Thomas P. Pettigrew dated December 22,
2003.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.15
    
    Manufacturing Services Agreement between the registrant
and Sanmina-SCI Corporation dated February 17, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    December 14, 200610.16
    
    Office Lease between the registrant and Selig Holdings
Company dated November 11, 2005.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.17
    
    First Amendment to Office Lease between the registrant
and Selig Holdings Company dated December 2, 2005.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.18
    
    Second Amendment to Office Lease between the registrant
and Selig Holdings Company dated August 4, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.19
    
    Venture Loan and Security Agreement between the
registrant and Horizon Technology Funding Company LLC
dated March 22, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.20
    
    Amendment to Venture Loan and Security Agreement between
the registrant and Horizon Technology Funding Company
LLC dated July 18, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.21
    
    Loan and Security Agreement between the registrant and
Silicon Valley Bank dated June 24, 2004.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.22
    
    Amendment to Loan and Security Agreement between the
registrant and Silicon Valley Bank dated March 10, 2005.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.23
    
    Amendment to Loan and Security Agreement between the
registrant and Silicon Valley Bank dated March 21, 2005.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.24
    
    Amendment to Loan and Security Agreement between the
registrant and Silicon Valley Bank dated June 29, 2005.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.25
    
    Amendment to Loan Documents between the registrant and
Silicon Valley Bank dated March 22, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 200610.26
    
    Amendment to Loan Documents between the registrant and
Silicon Valley Bank dated July 18, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    September 1, 2006




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##### Table of Contents



Incorporation by Reference HereinExhibitNumber
    
    Description
    
    Form
    
    Date10.27
    
    Warrant to Purchase Stock issued by registrant to
Horizon Technology Funding Company III LLC, dated March
22, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    October 10, 200610.28
    
    Warrant to Purchase Stock issued by registrant to
Horizon Technology Funding Company III LLC, dated March
22, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    October 10, 200610.29
    
    Offer Letter with Gwen Weld dated June 5, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 9, 200610.30
    
    Offer Letter with James Richardson dated October 2, 2006.
    
    Registration
Statement on Form
S-1, as amended
(File No.
333-137078)
    
    November 9, 200623.1
    
    Consent of PricewaterhouseCoopers LLP, independent
registered public accounting firm.
    
    Annual Report on
Form 10-K for the
fiscal year ended
December 31, 2006
(File No.
001-33196)
    
    March 15, 200724.1
    
    Power of Attorney.
    
    Annual Report on
Form 10-K for the
fiscal year ended
December 31, 2006
(File No.
001-33196)
    
    March 15, 200731.1*
    
    Rule 13a-14(a)/15d-14(a) Certification of Chief
Executive Officer.31.2*
    
    Rule 13a-14(a)/15d-14(a) Certification of Chief
Financial Officer.32.1*
    
    Section 1350 Certification of Chief Executive Officer.32.2*
    
    Section 1350 Certification of Chief Financial Officer.
 
 
    
    Registrant has omitted portions of the referenced exhibit and filed such exhibit separately
with the Securities and Exchange Commission pursuant to a grant of confidential treatment under
Rule 406 promulgated under the Securities Act of 1933.*
    
    Filed herewith.