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Exhibit (a)(1)(D)

        OFFER TO PURCHASE FOR CASH
All Outstanding Shares of Common Stock
of
Dot Hill Systems Corp.
at
$9.75 Net Per Share
by
Denali Acquisition Sub Corp.
a wholly owned subsidiary of
Seagate HDD Cayman
A wholly owned indirect subsidiary of
Seagate Technology Public Limited Company

THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:01 A.M. (EASTERN TIME)
ON OCTOBER 6, 2015, UNLESS THE OFFER IS EXTENDED OR EARLIER TERMINATED.

September 1, 2015

To Our Clients:

        Enclosed for your consideration are the offer to purchase, dated September 1, 2015 (the "Offer to Purchase"), and the related Letter of Transmittal (the "Letter of Transmittal," which, together with the Offer to Purchase and other related materials, as each may be amended or supplemented from time to time in accordance with the terms of the Acquisition Agreement (as described below), constitutes the "Offer") in connection with the Offer by Denali Acquisition Sub Corp. ("Purchaser"), a Delaware corporation and a wholly owned subsidiary of Seagate HDD Cayman, an exempted company with limited liability organized under the laws of the Cayman Islands ("Parent"), to purchase all of the outstanding shares of common stock, par value $0.001 per share (the "Shares"), of Dot Hill Systems Corp., a Delaware corporation ("Dot Hill"), at a price of $9.75 per Share, without interest thereon, net to the seller in cash, and subject to reduction for any applicable U.S. federal withholding, back-up withholding or other applicable tax withholdings, upon the terms and subject to the conditions set forth in the Offer to Purchase and the related Letter of Transmittal.

        We or our nominees are the holder of record of Shares held for your account. A tender of such Shares can be made only by us as the holder of record and pursuant to your instructions. The Letter of Transmittal is furnished to you for your information only and cannot be used by you to tender Shares held by us for your account.

        We request instructions as to whether you wish us to tender any or all of the Shares held by us for your account, upon the terms and subject to the conditions set forth in the Offer to Purchase and the related Letter of Transmittal.

        Your attention is directed to the following:



        If you wish to have us tender any or all of your Shares, please so instruct us by completing, executing, detaching and returning to us the instruction form below. An envelope to return your instructions to us is enclosed. If you authorize tender of your Shares, all such Shares will be tendered unless otherwise specified on the instruction form.

        Your prompt action is requested. Your instruction form should be forwarded to us in ample time to permit us to submit the tender on your behalf before the Expiration Date.

        Payment for Shares purchased pursuant to the Offer will in all cases be made only after timely receipt by the Depositary of (i) certificates representing the Shares tendered or timely confirmation of the book-entry transfer of such Shares into the account maintained by the Depositary at The Depository Trust Company (the "Book-Entry Transfer Facility"), pursuant to the procedures set forth in Section 3 of the Offer to Purchase, (ii) the Letter of Transmittal, properly completed and duly executed, with any required signature guarantees or an Agent's Message (as defined in the Offer to Purchase), in connection with a book-entry delivery, and (iii) any other documents required by the Letter of Transmittal. Accordingly, payment may not be made to all tendering stockholders at the same time depending upon when certificates for or confirmations of book-entry transfer of such Shares into the Depositary's account at the Book-Entry Transfer Facility are actually received by the Depositary.


Instruction Form with Respect to
Offer to Purchase for Cash
All Outstanding Shares of Common Stock
of
Dot Hill Systems Corp.
at
$9.75 Net Per Share
by
Denali Acquisition Sub Corp.
a wholly owned subsidiary of
Seagate HDD Cayman
a wholly owned indirect subsidiary of
Seagate Technology Public Limited Company

        The undersigned acknowledge(s) receipt of your letter and the enclosed offer to purchase, dated September 1, 2015 (the "Offer to Purchase"), and the related Letter of Transmittal (the "Letter of Transmittal", which, together with the Offer to Purchase and other related materials, as each may be amended or supplemented from time to time in accordance with the terms of the Acquisition Agreement, constitutes the "Offer"), in connection with the Offer by Denali Acquisition Sub Corp. to purchase all of the outstanding shares of common stock, par value $0.001 per share (the "Shares"), of Dot Hill Systems Corp.

        This will instruct you to tender the number of Shares indicated below held by you for the account of the undersigned, upon the terms and subject to the conditions set forth in the Offer to Purchase and the related Letter of Transmittal.

Number of Shares to be Tendered:

  SIGN HERE

                                     Shares*

 

  


Signature(s)

Dated                                         , 2015

 

  


Name(s)

*  Unless otherwise indicated, it will be assumed that all Shares held for the undersigned's account are to be tendered.

 

  


Address(es)

    

   

 


Zip Code



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