SC TO-C

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

(RULE 14d-100)

Tender Offer Statement Pursuant to Section 14(d)(1) or 13(e)(1) of

the Securities Exchange Act of 1934

Isilon Systems, Inc.

(Name of Subject Company)

Electron Merger Corporation

and

EMC Corporation

(Names of Filing Persons – Offeror)

COMMON STOCK, PAR VALUE $0.00001 PER SHARE

(Title of Class of Securities)

46432L104

(Cusip Number of Class of Securities)

Paul T. Dacier, Esq .

June D. Duchesne, Esq.

EMC Corporation

176 South Street

Hopkinton, Massachusetts 01748

(508) 435-1000

(Name, Address and Telephone Number of Person Authorized to Receive Notices

and Communications on Behalf of Filing Persons)

Copies to:

Margaret A. Brown, Esq.

Skadden, Arps, Slate, Meagher & Flom LLP

One Beacon Street

Boston, MA 02108

(617) 573-4800

CALCULATION OF FILING FEE

Transaction valuation*	Amount of filing fee
Not Applicable	Not Applicable

* A filing fee is not required in connection with this filing as it relates solely to preliminary communications made before the commencement of a tender offer.

¨ Check box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:	Not applicable.	Filing Party:	Not applicable.
Form or Registration No.:	Not applicable.	Date Filed:	Not applicable.

þ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

þ third-party tender offer subject to Rule 14d-1.

¨ issuer tender offer subject to Rule 13e-4.

¨ going-private transaction subject to Rule 13e-3.

¨ amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer. ¨

Additional Information and Where to Find it.

This Tender Offer Statement on Schedule TO (this “Statement”) relates to a planned tender offer by Electron Merger Corporation (“Purchaser”), a wholly owned subsidiary of EMC Corporation (“EMC”), for all shares of outstanding common stock of Isilon Systems, Inc. (“Isilon”), to be commenced pursuant to an Agreement and Plan of Merger, dated as of November 14, 2010, by and among EMC, the Purchaser and Isilon.

The tender offer referred to in this Statement has not yet commenced. This Statement is neither an offer to purchase nor a solicitation of an offer to sell any shares of Isilon. The solicitation and the offer to buy shares of Isilon common stock will be made pursuant to an offer to purchase and related materials that EMC and Purchaser intend to file with the U.S. Securities and Exchange Commission (the “SEC”). At the time the tender offer is commenced, EMC and Purchaser intend to file a Tender Offer Statement on Schedule TO containing an offer to purchase, forms of letters of transmittal and other documents relating to the tender offer and Isilon intends to file a Solicitation/Recommendation Statement on Schedule 14D-9 with respect to the tender offer. EMC, Purchaser and Isilon intend to mail these documents to the stockholders of Isilon. These documents will contain important information about the tender offer and stockholders of Isilon are urged to read them carefully when they become available. Investors and stockholders of Isilon will be able to obtain a free copy of these documents (when they become available) and other documents filed by EMC, Purchaser and Isilon with the SEC at the website maintained by the SEC at www.sec.gov. In addition, the tender offer statement and related materials may be obtained for free (when they become available) by directing such requests to EMC Corporation at Attention: Office of the General Counsel, 176 South Street, Hopkinton, MA 01748, or from Isilon Systems, Inc. at Attention: Investor Relations Department, 3101 Western Avenue, Seattle, Washington 98121.

Item 12. Exhibits.

99.1 Text of article posted on EMC website, dated November 15, 2010

99.2 Text of e-mail to Isilon Employees delivered on November 15, 2010

EX-99.1

Exhibit 99.1

EMC To Acquire Isilon

Well, today’s news confirmed what was long discussed — EMC’s intent to acquire Isilon. The full webcast, plus supporting materials, can be found here.

So, what’s this all about? And what might be different going forward?

Glad you asked ...

Before We Begin

I went back through my blog, and found a raft of “EMC To Acquire [xyz]” posts over the years. I’m sure I’m not done yet :-)

In general, I try and do a reasonable job in sharing our thoughts on context, rationale and likely future implications. Just about all of them have turned out to be reasonably accurate — so far!

What’s The Opportunity?

Everyone knows that the amount of digital information we all create and use continues to expand with no real end in sight. During 2009, the forecast was made that we’d see 44x growth in volume by the end of this decade.

Sitting where we are at the end of 2010, that growth forecast may have been conservative.

Pat Gelsinger (ex of Intel) is fond of saying that the rate of information growth appears to be outstripping the famous Moore’s Law of semiconductor evolution.

Yes, there’s a tie-in with cloud.

One of the interesting properties of cloud (whether it be private, public or something else) is that it makes compute easier to consume: lower cost, more agility, less effort, etc. And when something becomes easier to consume, people tend to consume more of it.

If one can think of cloud as “big compute”, it’s easy to see the interactions and dependencies with the corresponding need for “big data”.

Indeed, we’re all dazzled with the ever-growing variety of unique applications and business models that harness enormous amounts of this new digital wealth. Some of this information is structured (think tables and analytics), but most of it is unstructured (think files and objects).

Compared to the more traditional world of enterprise IT applications (email, ERP, etc.) we’re talking about an entirely different kind of storage world: petabytes vs. terabytes. Discussions of scale can’t simply be reduced to marketing hand-waving: specific architectures are needed around very focused use cases.

Enter Isilon

Over the years, Isilon has done an excellent job by focusing on a specific set of “big data” use cases that other vendors haven’t been able to do well: petabyte-class file systems with enormous sequential performance, and exceptionally attractive capex/opex numbers.

For these specific use cases, we quickly learned that EMC couldn’t compete well as we would have liked in these focused situations. Neither could NetApp, HP, or anyone else for that matter.

In this category, there was Isilon — and then everyone else.

Yes, we call it “scale-out NAS”, but — since there’s very little precision in how these terms are used — it’s more helpful to focus on how customers are using Isilon’s products, rather than attempt to precisely define an industry category. IDC offers the view that this market is around $2B today, potentially growing to $6B by 2014.

EMC’s proposed acquisition of Isilon is predicated on the belief that — not only will we see far more of these use cases in the future — but there are obvious synergies between Isilon and the rest of EMC’s portfolio and broader strategies.

Of Files And Objects

Isilon’s model is exceptionally well suited to environments where you have a lot of data sitting in a small number of locations — a strongly centralized model.

Thinking in terms of big, fast and cost-effective NAS isn’t that far off. And Isilon’s unique credentials here are generally well understood.

Many of us see the Atmos model as extremely complementary for a different type of big data — billions of objects, created and used geographically . one where rich metadata is needed to help manage the challenge of information logistics.

Synergies Abound

Place Isilon square in the middle of EMC’s core storage businesses, and it’s easy to see a first round of obvious synergies: access to EMC’s sales and partner organizations, global customer support, integration, solutions, etc. All at once, the proven Isilon technology will be sold, integrated and supported by the #1 vendor in the industry.

We’ve seen this “EMC Effect” before — the usual result is a far more rapid adoption by customers and partners alike.

But there’s potential technology synergy here as well. Much of this data needs to be backed up, archived or otherwise intelligently managed once it’s no longer primary storage — a lot of the EMC portfolio can help here over time. Not to mention access to a variety of data deduplication and compression technologies to help improve the Isilon value proposition even further.

There’s more, but I think you can see the potential.

The Big EMC Picture

During the investor call, Pat Gelsinger used a nice representation of how all the pieces are starting to come together.

For traditional enteprise workloads, EMC has always done well in creating storage platforms for the bread-and-butter of IT today: ERP, collaboration, database, etc.

Isilon, taken together with Atmos, creates a portfolio of “big data” storage platforms that house enormous amounts of unstructured data: files and objects.

Our Greenplum database acquisition spans both camps: it meets the growing enterprise needs around real-time analytics, while have the architectural chops to support “big data” applications as well.

Supporting this are the collected EMC disciplines around information protection and security: Avamar, Recoverpoint, Data Domain, RSA, Archer et. al.

Embed this picture within the broader landscape of private clouds (leveraging VMware among others) and an even more compelling picture emerges.

What Does This Mean Going Forward?

First, this acquisition serves as clear evidence that EMC believes this category of storage platform (petabyte-class scale-out NAS) will be ever more important going forward. This acquisition also reflects our belief that purpose-built architectures will be more attractive vs. simply re-positioning existing technologies.

Second, you’re seeing a strong enthusiasm for EMC to invest in our core franchise — storage — by using a mixture of R&D *and* targeted M&A. If nothing else convinces you that EMC is deadly serious about the storage market, this should help :-)

Third, this indicates our belief that “big data” (whether structure or unstructured, file or object, etc.) is one of the next strategic battlegrounds in the storage industry. You’re also seeing a portfolio approach from EMC, and not just a point product.

Finally, I believe that — going forward — it’ll be increasingly difficult to separate the cloud discussion from big data. Both derive efficiencies from scale. Both are being used to create new kinds of applications to extract value from information in ways we haven’t seen before. Both are around IT that’s built differently, operated differently and consumed differently.

Competitive Noise?

I’m sure that there will be some predictable noise from all the usual suspects — EMC plays in a very noisy and competitive segment of the market. There will be those that claim that their existing products serve the needs of this segment. There will be those that claim that this market segment isn’t that important, or only a niche at best. Or, my perennial favorite, that EMC is creating yet-another-storage-silo.

All comments are fair game, as always.

We’re very excited at the prospect of the proven Isilon team joining the EMC family — welcome!

We’re making our play in this important space, and we’re all looking forward to big things in the near future.

As are our customers :-)

------------- Important Information Below -------------

Important Information

This blog post (this “Statement”) relates to a planned tender offer by Electron Merger Corporation (“Purchaser”), a wholly owned subsidiary of EMC Corporation (“EMC”), for all shares of outstanding common stock of Isilon Systems, Inc. (“Isilon”), to be commenced pursuant to an Agreement and Plan of Merger, dated as of November 14, 2010, by and among EMC, the Purchaser and Isilon.

The tender offer referred to in this Statement has not yet commenced. This Statement is neither an offer to purchase nor a solicitation of an offer to sell any shares of Isilon. The solicitation and the offer to buy shares of Isilon common stock will be made pursuant to an offer to purchase and related materials that EMC and Purchaser intend to file with the U.S. Securities and Exchange Commission (the “SEC”). At the time the tender offer is commenced, EMC and Purchaser intend to file a Tender Offer Statement on Schedule TO containing an offer to purchase, forms of letters of transmittal and other documents relating to the tender offer and Isilon intends to file a Solicitation/Recommendation Statement on Schedule 14D-9 with respect to the tender offer. EMC, Purchaser and Isilon intend to mail these documents to the stockholders of Isilon. These documents will contain important information about the tender offer and stockholders of Isilon are urged to read them carefully when they become available. Investors and stockholders of Isilon will be able to obtain a free copy of these documents (when they become available) and other documents filed by EMC, Purchaser and Isilon with the SEC at the website maintained by the SEC at www.sec.gov. In addition, the tender offer statement and related materials may be obtained for free (when they become available) by directing such requests to EMC Corporation at Attention: Office of the General Counsel, 176 South Street, Hopkinton, MA 01748. Investors and stockholders of Isilon may obtain a free copy of the solicitation/recommendation statement and other documents (when they become available) from Isilon by directing requests to Isilon Systems, Inc. at Attention: Investor Relations Department, 3101 Western Avenue Seattle, Washington 98121. 

EX-99.2

Exhibit 99.2

To:	All Isilon Employees
From:	Joe Tucci, EMC Chairman & CEO
Date:	November 15, 2010
Subject:	Welcome to EMC

Hello to everyone at Isilon. On behalf of EMC people around the world, please know that we are absolutely thrilled to have you join the EMC family!

You are an amazing jewel of a company on so many fronts. We at EMC are deeply impressed with your talented people, your pioneering storage offerings that enable businesses to innovate at the scale of the cloud, your stellar reputation with customers, and your track record of rapid growth. Sujal and I foresee an exciting future as Isilon joins EMC’s Information Infrastructure Products business, which is led by Pat Gelsinger, who I know will be speaking with you later today.

Bringing Isilon into the EMC family is all about accelerating growth by capitalizing on a very large and rapidly changing market opportunity—“big data,” meaning the massive amounts of data produced by a new generation of applications like gene sequencing, online streaming, and seismic interpretation. By combining Isilon’s and EMC’s solutions, we will put ourselves in the strongest possible position to help our customers store and manage the vast amounts of “big data” that the transformational cloud computing wave is washing into their businesses. Together, we’ll be able to offer the most complete portfolio of storage offerings for the physical IT world of today and the fast-emerging virtual cloud computing world of tomorrow.

Our two companies have much in common. We share a vision of where IT is going. We share a passion for innovating to solve customers’ most challenging problems. Our technologies are highly complementary. For example, Isilon and EMC’s Atmos object storage create a great one-two punch for storing and managing big data. What’s more, we both love to win in the marketplace by delivering the industry’s most innovative, cost-effective, and highest quality products and services. I want to assure you that EMC truly knows how to acquire innovative companies (like yours) that have become leaders in their business segment, integrate them smoothly and successfully, and then empower them to excel.

To accelerate your growth and help you continue to excel, EMC intends to increase R&D investment in Isilon. We will also leverage our global sales and marketing organization, which is over 12,000 strong and operates in more than 83 countries. And we will also leverage our extensive network of channel and alliance partners as well as our global services organization to ensure even broader adoption of your portfolio of leading products. We expect the combined revenue of these two highly complementary storage offerings (Isilon and Atmos) to reach a $1 billion run-rate during the second half of 2012.

Together, EMC and Isilon are positioned at the intersection of cloud computing and Big Data. Given what’s going on in the IT world right now, I can’t think of a better place to be. I look forward to spending time with you in the near future.

All the best,

Joe

********

Important Information

This email (this “Statement”) relates to a planned tender offer by Electron Merger Corporation (“Purchaser”), a wholly owned subsidiary of EMC Corporation (“EMC”), for all shares of outstanding common stock of Isilon Systems, Inc. (“Isilon”), to be commenced pursuant to an Agreement and Plan of Merger, dated as of November 14, 2010, by and among EMC, the Purchaser and Isilon.

The tender offer referred to in this Statement has not yet commenced. This Statement is neither an offer to purchase nor a solicitation of an offer to sell any shares of Isilon. The solicitation and the offer to buy shares of Isilon common stock will be made pursuant to an offer to purchase and related materials that EMC and Purchaser intend to file with the U.S. Securities and Exchange Commission (the “SEC”). At the time the tender offer is commenced, EMC and Purchaser intend to file a Tender Offer Statement on Schedule TO containing an offer to purchase, forms of letters of transmittal and other documents relating to the tender offer and Isilon intends to file a Solicitation/Recommendation Statement on Schedule 14D-9 with respect to the tender offer. EMC, Purchaser and Isilon intend to mail these documents to the stockholders of Isilon. These documents will contain important information about the tender offer and stockholders of Isilon are urged to read them carefully when they become available. Investors and stockholders of Isilon will be able to obtain a free copy of these documents (when they become available) and other documents filed by EMC, Purchaser and Isilon with the SEC at the website maintained by the SEC at www.sec.gov. In addition, the tender offer statement and related materials may be obtained for free (when they become available) by directing such requests to EMC Corporation at Attention: Office of the General Counsel, 176 South Street, Hopkinton, MA 01748. Investors and stockholders of Isilon may obtain a free copy of the solicitation/recommendation statement and other documents (when they become available) from Isilon by directing requests to Isilon Systems, Inc. at Attention: Investor Relations Department, 3101 Western Avenue Seattle, Washington 98121.