<PAGE>

                          AGREEMENT OF EXISTING PARTNERS
                  OF RACKSPACE, LTD. TO FACILITATE PUBLIC OFFERING

       This Agreement is made this 27 day of March, 2000, by and between
Rackspace, Ltd. ("Rackspace" or the "Company" or the "Partnership") and all of
its present partners (which include Red Hat, Thomas Weisel and Norwest, as
defined below), all of whom are signatories to this Agreement (the "Partners").
Rackspace.com, Inc., a newly formed, Delaware corporation, is also made a party
to this Agreement ("New Rackspace").   In addition, Brian Bell and Edwin Grubbs
are made parties to this agreement with respect to the partnership interests
held by them as assignees.

NEW INVESTORS TO BE INCLUDED

       Under the terms of the Fourth Amendment to Agreement of Limited
Partnership of Rackspace, Ltd., it is expressly contemplated that the General
Partner may cause Rackspace to issue up to  530,035.34 Class C Units (the
"Additional Units") to one or more additional persons or entities (the "New
Investors"), provided that the aggregate purchase price per Unit is not less
than $5.66 per Unit.  The General Partner may also issue to the New Investors a
warrant to purchase an amount of Class C Units determined by dividing $3,000,000
by the greater of the $18.24 or the mid-point in the filing range (the
"Mid-point") set forth in the preliminary prospectus (commonly referred to as
the "red herring") which is first circulated by the Company.   It is the
intention and agreement of the parties hereto that such New Investors shall have
the benefits and obligations of the Holders as set forth herein, and that they
may become signatories to this Agreement without any further consent or
agreement of the parties to this agreement.

CERTAIN REFERENCES

The Agreement of Limited Partnership of Rackspace, Ltd. and the four existing
amendments thereto, are sometimes collectively referred to herein as the
"Partnership Agreement."  The Registration Rights Agreement dated November 30,
1999, as amended on February 22, 2000 is referred to as the "Rights Agreement."
The Support Agreement dated December 29, 1998, as amended on November 30, 1999
and again on February 22, 2000 is referred to as the "Support Agreement." For
the purposes of this agreement, Richard Yoo is referred to as "Yoo," Pat Condon
is referred to as "Condon," Dirk Elmendorf is referred to as "Elmendorf," Trout,
Ltd. is referred to as "Trout," Macroweb, LC is referred to as the "General
Partner," First Inning Investors, L.P., is referred to as "First Inning," Isom
Capital Partners I, L.P. is referred to as "Isom," The Hamilton Companies LLC is
referred to as "Hamilton," Beaulieu River Capital LC is referred to as
"Beaulieu," MiniPat & Company, Ltd. is referred to as "MiniPat," 2M Technology
Ventures, L.P., is referred to as "2M," Trango Capital, L.L.C. is referred to as
"Trango,"Red Hat, Inc. is referred to as "Red Hat," Norwest Venture Partners
VII, L.P. is referred to as "Norwest,"  Tailwind Capital Partners 2000, L.P. is
referred to as "Thomas Weisel," Graham M. Weston is referred to as "Weston,"
Morris A. Miller is referred to as


                                          1
<PAGE>

"Miller," Brian Bell is referred to as "Bell" and Edwin Grubbs is referred to
herein as "Grubbs."  The Partners, Bell, Grubbs and the New Investors are
sometimes collectively referred to herein as the "Holders."



PURPOSE OF AGREEMENT

This Agreement is made by and amongst Rackspace, New Rackspace, the Holders and
the New Investors, if any, to satisfy certain requirements and follow certain
recommendations of the Underwriters (defined below) and to facilitate the
registration and sale of the stock of New Rackspace in a public offering
registered under the Securities Act of 1993 (inclusive of the sale of such
stock, the "IPO") underwritten by Deutsche Bank, Securities, Inc., Bear, Stearns
& Co. Inc. and Thomas Weisel Partners LLC and certain other underwriters (the
"Underwriters").  The IPO will benefit the Holders as they will become
shareholders of New Rackspace pursuant to the terms of this Agreement.  This
Agreement is entered into contemporaneously with the execution of the Fourth
Amendment of the Partnership Agreement, whereby Red Hat, Thomas Weisel and
Norwest become Class C Limited Partners of the Partnership.


ACTIONS TO BE TAKEN UNDER THIS AGREEMENT

END OF OPTION RIGHTS.  The  Underwriters have requested that Weston, Miller,
Condon, Elmendorf and Yoo end their rights under Section 17 of the Second
Amendment to the Partnership Agreement to forego salary and receive options to
acquire additional interests in the Company (and New Rackspace, its successor).
If these rights are not terminated, these individuals will have the right to
acquire a substantial amount of New Rackspace's stock at prices substantially
below market value which will likely result in large earnings charges against
New Rackspace. Weston, Miller, Condon, Elmendorf and Yoo have agreed to waive
these rights.

REGISTRATION RIGHTS.  Certain of the Partners have demand and piggyback
registration rights under the terms of the Rights Agreement.   Red Hat, Norwest,
Thomas Weisel and the New Investors do not have such registration rights,
whether demand rights or piggyback rights.  The  parties desire to amend the
existing Rights Agreement to include Red Hat, Norwest, Thomas Weisel and the New
Investors as Investors under the Registration Rights Agreement.

CONVERSION TO CORPORATION.  The General Partner has broad powers to cause the
Company to convert to a corporation, including for the purpose of  facilitating
an IPO.  In order to facilitate the description of the succession of  Rackspace
to New Rackspace, the underwriters have suggested that the Holders transfer all
of their interests in the Partnership (the "Units")  to New Rackspace, in
exchange for common stock in New Rackspace (the "Common Stock").  The Partners
have agreed to make this exchange


                                          2
<PAGE>

pursuant to the terms of this Agreement and agree to allow this exchange,
whether or not the IPO occurs.

AMENDMENT OF SUPPORT AGREEMENT.  The parties desire to amend the Support
Agreement to include as Class C Limited Partners, Red Hat, Norwest, Thomas
Weisel and the New Investors.

       NOW, THEREFORE, FOR AND IN CONSIDERATION OF THE MUTUAL PROMISES HEREIN
MADE, THE PARTIES AGREE AS FOLLOWS:

OPTIONS

TERMINATION OF OPTION RIGHTS.  Provided that the IPO  is completed by July 31,
2000, effective April 30, 2000, Miller, Weston, Yoo, Elmendorf and Condon will
have no further right to forgo salary and receive options to acquire Units in
the Company (or stock in New Rackspace) under Section 17 of the Second Amendment
to the Partnership Agreement. Miller, Weston, Elmendorf and Condon each made an
election on January 1, 2000 to receive options in lieu of salary.  Yoo hereby
waives his right to receive options under Section 17 in lieu of salary for the
four-month period ending April 30, 2000.  Commencing January 1, 2000 and ending
April 30, 2000, Miller, Weston, Elmendorf and Condon will continue to forgo
salary and receive options to acquire Units in accordance with the terms of
Section 17 of the Second Amendment to the Partnership Agreement.

SUPPORT AGREEMENT

AMENDMENT TO SUPPORT AGREEMENT.  The Support Agreement, as amended, is further
amended to include, for the purpose of Paragraph 1,  Norwest, Red Hat, Thomas
Weisel and the New Investors, as "Class C Limited Partners."



REGISTRATION RIGHTS

       1.     CORRECTION TO REGISTRATION RIGHTS AGREEMENT. The Rights Agreement
              does not include Trango as an "Investor."  The Rights Agreement is
              hereby amended to include  Trango as an Investor, as if it had
              initially executed the Rights Agreement.

       2.     LOCK-UP AGREEMENT.  The Underwriters have required that each of
              the Holders agree not to sell their stock in New Rackspace for a
              period of 180 days following the IPO and the parties to the Rights
              Agreement are required to execute the same under the obligations
              set forth in the Rights Agreement. Therefore, each of the Holders
              agree to enter into the Lock-up Agreement attached as Exhibit A
              and deliver the same to the offices of the Company upon the
              execution of this Agreement.


                                          3
<PAGE>

       3.     PIGGYBACK AND DEMAND REGISTRATION RIGHTS- RED HAT,  THOMAS WEISEL,
              NEW INVESTORS, NORWEST.  The parties agree that Red Hat, Norwest,
              New Investors and Thomas Weisel shall have piggyback and demand
              registration rights in accordance with the provisions of Section 2
              and Section 3 of the Rights Agreement with respect to  the Units
              held by them  (and Common Stock acquired incident to the
              Exchange), shall be considered Holders of Registrable Securities
              with respect to all the Units (and Common Stock acquired incident
              to the Exchange) held by them for purposes of the Rights Agreement
              and each shall have all the benefits and obligations of an
              Investor under the Rights Agreement, the same as if they were
              direct signatories to the Rights Agreement.  Upon the Exchange (as
              defined below),  the parties agree that without further act of the
              parties, New Rackspace will be substituted in place of the Company
              for all purposes of the Rights Agreement.

       EXCHANGE OF INTERESTS

       EXCHANGE OF INTERESTS.  To accomplish various business purposes, the
       General Partner of the Partnership has the ability to cause the
       Partnership to convert to a corporation.  The Partnership Agreement
       specifically contemplates that the Company, through a successor entity,
       will have an IPO and the General Partner is given broad powers to change
       the form of the Company from a limited partnership to a corporation by
       merger or contribution of assets and liabilities, in order to effect an
       IPO.   In addition, if the Company does not have an IPO, the General
       Partner has determined that it may nevertheless be beneficial to convert
       to a corporation.  At the request of the Underwriters, the General
       Partner desires that, rather than a merger or contribution of assets and
       liabilities, the Holders exchange their Units for Common Stock, and that
       this exchange occur with the possibility that the New Rackspace may not
       complete the IPO.  The exchange will take place on a one Unit for one
       share of Common Stock basis, except for Yoo, Elmendorf, Condon, Bell,
       Grubbs and Macroweb, each of whom will receive slightly less than one
       share of Common Stock per Unit exchanged, and except for Trout, which
       will receive slightly more than one share of Common Stock per Unit
       exchanged.  Each of the Holders agree that at such time that the General
       Partner contributes all of its Units to New Rackspace, the Units of such
       Holder and of all of the Holders, without any further act of the
       Holders, shall be transferred to New Rackspace in exchange for Common
       Stock in proportion to the Holders' positive Capital Account balances,
       adjusted by treating the Partnership as having liquidated and its
       property sold at fair market value, and gains and losses allocated in
       accordance with Section 11.4 of the  Partnership Agreement, which
       proportions are set forth below (the "Exchange").   The Common Stock
       received from New Rackspace will have an appropriate legend indicating
       that it is subject to the restrictions contained in the Partnership
       Agreement (which restriction shall be removed after the IPO, if it
       occurs), and that it is restricted stock and may not be sold without an
       opinion of counsel to the satisfaction of New Rackspace that such sale
       will not be in violation of the provisions of the Securities Act of 1933.
       The


                                          4
<PAGE>

       Holders agree that no fractional shares of Common Stock will be issued,
       and as a result fractional Units shall be rounded to the nearest whole
       number as set forth below:






<TABLE>
<CAPTION>
              Partner                   Units Exchanged        Common Stock to be
              -------                   ---------------        received upon Exchange
                                                               ----------------------
<S>                                 <C>                         <C>
              Yoo                         3,600,000               3,565,714
              Condon                        800,000                 792,380
              Elmendorf                     400,000                 396,190
              Grubbs                         50,000                  49,523
              Bell                           50,000                  49,523
              Macroweb                       10,000                   9,904
              Trout                       7,232,856.2             7,279,619
              First Inning                  619,047.61              619,048
              Isom                        1,219,047.62            1,219,048
              Hamilton                      476,190.48              476,190
              Beaulieu                      357,142.86              357,143
              MiniPat                        95,238.10               95,238
              2M                            119,047.61              119,048
              Red Hat                       353,356.89              353,357
              Norwest                     1,015,901               1,015,901
              Thomas Weisel                  53,003.53               53,003
                                             ---------               ------

              Total                      16,450,831.94*          16,450,829*
</TABLE>

       *Subject to adjustment for Units held by the New Investors which will be
       exchanged on a one Unit for one share of Common Stock basis and subject
       to further adjustment for the exchange of any Units issued pursuant to
       the Warrant in favor of Trango Capital, LLC (380,952.38 Units), or any
       other option holder, all of which will be exchanged on the basis of one
       share of Common Stock for each Unit exchanged.

       DIRECTORS/RIGHTS OF PARTNERS/PROXIES

       1.     DIRECTORS OF NEW RACKSPACE.   The Class C Units Holders, The
              Hamilton Companies, LLC  and Trout have the right to appoint
              directors of New Rackspace under the terms of the Second Amendment
              to the Partnership Agreement (the "Voting Agreement").   However,
              these rights end when and if Trout, Ltd. waives its right to
              appoint five of the seven directors.  Miller and Weston are
              currently the sole directors of New Rackspace.    In order to
              timely


                                          5
<PAGE>

              appoint five additional members to New Rackspace's board of
              directors, each of the Holders hereby grant to the General
              Partner, their irrevocable proxy to vote all of the shares of
              Common Stock in New Rackspace received by them as a result of the
              Exchange, to elect and name up to five additional members to the
              board of directors of New Rackspace.  This proxy will expire on
              the earlier to occur of July 31, 2000, the date immediately prior
              to the IPO, or the date seven directors are named to New
              Rackspace's board of directors.  The General Partner agrees to
              consult with each of the Partners prior to naming any of the
              directors.   Effective the date immediately prior to the IPO, the
              Voting Agreement will terminate.  The General Partner agrees that
              it will not exercise the proxies granted under this paragraph in
              order to appoint persons who are related to Morris A. Miller or
              Graham M. Weston.

       2.     CONVERSION TO CORPORATION PRIOR TO IPO.   It is likely that the
              General Partner will determine that it is necessary to convert to
              a corporation at a time when it is not certain whether or not the
              Company will effect the IPO.   The Holders agree that all
              pre-emptive rights, rights of first refusal, share transfer
              restrictions, re-purchase rights, voting agreements, parallel exit
              rights and all other rights contained in the Partnership
              Agreement, and the Support Agreement that do not exist as a
              consequence of the application of the general corporate provisions
              of Delaware corporation law (collectively, the "Rights and
              Obligations"), shall be binding on and inure to the benefit of all
              New Rackspace's shareholders and on New Rackspace, the same as
              such Rights and Obligations are presently binding on the Partners
              and the Company; provided that all of such Rights and Obligations
              shall terminate immediately prior to the IPO.  The parties also
              agree that the Support Agreement shall terminate immediately prior
              to the IPO.  If, however, the IPO does not take place by July 31,
              2000, New Rackspace agrees to prepare the documentation necessary
              to ensure that all such Rights and Obligations are binding on New
              Rackspace, the Holders and all other shareholders of New Rackspace
              (such documents are referred to as the "Documents"), with New
              Rackspace having the discretion, to the extent reasonably
              exercised, to modify such Rights and Obligations to the extent
              necessary to accommodate the differences between a limited
              partnership and a corporation.  The Holders agree to execute
              Documents upon receipt so long as the Documents substantially
              conform to the Rights and Obligations set forth in the Partnership
              Agreement.

       3.     STOCK PLAN.   In order for New Rackspace to adopt a qualified
              incentive stock option plan, the shareholders of New Rackspace
              must adopt the plan.  The General Partner has selected a highly
              flexible plan based upon the recommendations of its SEC counsel.
              In order to approve the plan prior to the IPO, the Holders each
              give the General Partner, their irrevocable proxy to approve the
              plan recommended by the Company's counsel.  Therefore, each of the
              Holders give the General Partner their irrevocable proxy with
              respect to the Common Stock received by them incident to the
              Exchange, to exercise the voting rights of such stock to approve
              any incentive stock option plan


                                          6
<PAGE>

              (including qualified and non-qualified stock options), employee
              stock purchase plan, director option and compensation plan, and
              any other plan which is designed to enable New Rackspace to
              compensate, reward and/or incentivize its employees, agents,
              consultants and directors.  This proxy will end on the earlier to
              occur of July  31, 2000 or the IPO.

       4.     INDEMNITY OF GENERAL PARTNER.   Upon the Exchange, Macroweb shall
              no longer be the general partner of Rackspace, Ltd., but rather
              Rackspace Management, LC shall be the new general partner.  The
              Company acknowledges and agrees that the indemnity obligations
              contained in the Partnership Agreement shall continue to be
              enforceable by Macroweb and its members, officers and agents,
              against the Company and against New Rackspace, with respect to
              acts and omissions occurring while Macroweb was the general
              partner of the Company.

       MISCELLANEOUS

       1.     REPRESENTATION The parties to this Agreement acknowledge that the
              law firm of Matthews and Branscomb, P.C. has assisted in the
              preparation of this document on behalf of and as counsel for
              Trout, Ltd. and the General Partner only, and further acknowledge
              that the Partnership will pay the fees and expenses associated
              with such services.

       2.     MULTIPLE COUNTERPARTS.   This Agreement may be executed in one or
              more  counterparts, each of which shall be deemed an original but
              all of which together will constitute one and the same instrument.


       Executed as of the date first written above.

                              RACKSPACE, LTD.

                              By:  Macroweb, LC
                              Its: General Partner

                                    /s/ Graham M. Weston
                                   -----------------------------------
                                   Graham M. Weston, Member

                                   /s/ Morris A. Miller
                                   -----------------------------------
                                   Morris A. Miller, Member


                              GENERAL PARTNER:

                              Macroweb, LC


                                          7
<PAGE>

                                    /s/ Morris A. Miller
                                   ---------------------------------------------
                                   Morris A. Miller, Member

                                    /s/ Graham M. Weston
                                   ---------------------------------------------
                                   Graham M. Weston, Member


                              LIMITED PARTNERS:

                               /s/ Richard Yoo
                              --------------------------------------------------
                              Richard Yoo

                              /s/ Dirk Elmendorf
                              --------------------------------------------------
                              Dirk Elmendorf

                              /s/ Patrick Condon
                              --------------------------------------------------
                              Patrick Condon


                              Trout, Ltd.
                              By:  Knightsbridge, L.C., General Partner

                                   By: /s/ Morris A. Miller
                                      -------------------------------------

                              Isom Capital Partners I, L.P.
                              By:  BESK Funding, Inc., General Partner

                                   By: /s/ S. James Bishkin
                                      -------------------------------------
                                        S. James Bishkin, President

                              First Inning Investors, L.P.
                              By:  Trango Capital L.L.C., General Partner

                                   By: /s/ Quincy J. Lee
                                      -------------------------------------
                                        Quincy J. Lee, Manager

                              The Hamilton Companies LLC

                                   By:  /s/ Frederick Hamilton
                                      -------------------------------------


                                          8
<PAGE>

                              Beaulieu River Capital LC (formerly,
                              Weston Investment Interest, L.L.C.)

                              By: /s/ Graham Weston
                                 ------------------------------------------

                              Title:  Member
                                    ---------------------------------------

                              MiniPat & Company, Ltd.

                              By:  /s/ Patrick Condon
                                 ------------------------------------------


                              2M Technology Ventures, L.P.
                              By:  2M Technology Group, L.L.C.
                                   Its: General Partner

                              By:  /s/ Steven Leeke
                                 ------------------------------------------

                              Red Hat, Inc.

                              By:  /s/ Walter McCormick
                                 ------------------------------------------


                              Norwest Venture Partners VII, L.P.

                              By:  /s/ George Still, Jr.
                                 ------------------------------------------
                                   General Partner

                               /s/ Brian Bell
                              ---------------------------------------------
                              Brian Bell

                               /s/ Edwin Grubbs
                              ---------------------------------------------
                              Edwin Grubbs


                                          9
<PAGE>

                              Tailwind Capital Partners 2000, L.P.

                              By:  Thomas Weisel Capital Partners LLC,
                                   general partner

                                   By: /s/ David A. Baylor
                                      ---------------------------
                                   David A. Baylor, General Counsel



                              NEW INVESTORS:



                                          10
<PAGE>

                          AGREEMENT OF EXISTING PARTNERS
                  OF RACKSPACE, LTD. TO FACILITATE PUBLIC OFFERING
                     Separate Signature Page for New Investors




With respect to the 466,431 Class C Units purchased by Sequoia Capital Franchise
Fund for $2,640,000.

Sequoia Capital Franchise Fund

By: /s/ illegible
   --------------------------



With respect to the 63,604 Class C Units purchased by Sequoia Capital Franchise
Partners for $360,000.
Sequoia Capital Franchise Partners

By: /s/ illegible
   --------------------------



RACKSPACE, LTD.

By:  Macroweb, LC, general partner

     By: /s/ Graham Weston
        --------------------------

     Its:  Member
         --------------------------



                                          11