<PAGE>

THIS WARRANT HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
AMENDED, OR ANY STATE SECURITIES LAWS. NO SALE OR DISPOSITION MAY BE EFFECTED
WITHOUT (i) EFFECTIVE REGISTRATION STATEMENTS RELATED THERETO, (ii) AN OPINION
OF COUNSEL FOR THE HOLDER, REASONABLY SATISFACTORY TO RACKSPACE, THAT SUCH
REGISTRATIONS ARE NOT REQUIRED, (iii) RECEIPT OF NO-ACTION LETTERS FROM THE
APPROPRIATE GOVERNMENTAL AUTHORITIES, OR (iv) OTHERWISE COMPLYING WITH THE
PROVISIONS OF SECTION 7 OF THIS WARRANT.

                                 RACKSPACE, LTD.

                               WARRANT TO PURCHASE
                             SHARES OF COMMON STOCK

                       March 27, 2000 ("Date of Grant")

         THIS CERTIFIES THAT, for value received, and subject to the provisions
and upon the terms and conditions hereinafter set forth, Norwest Venture
Partners (the "Holder") is entitled to subscribe for and purchase, at an
exercise price per unit or share (as set forth in Section 1(a) and as adjusted
herein, the "Warrant Price"), up to that number of Class C Units (having the
rights of a Class C Limited Partner), or shares of fully paid and nonassessable
Common Stock (the "Shares") of RACKSPACE, LTD., a Texas limited partnership or
its successor corporation ("Rackspace"), as determined by dividing $3,000,000 by
the Warrant Price (the "Warrant Coverage").

     1.   WARRANT PRICE; TERM

          (a) WARRANT PRICE. The Warrant Price shall be the greater of (i)
$18.24 [a number determined by dividing $300,000,000 by 16,450,831.94, the
number of currently outstanding units of Rackspace], or (ii) the price which is
at the mid-point of the filing range of Rackspace's Form S-1 filed under the
Securities Act of 1933, which is circulated as its preliminary prospectus (the
"Mid-point price").

          (b) TERM. The purchase right represented by this Warrant is
exercisable, in whole or in part, at any time and from time to time one (1) year
from the Date of Grant; provided that it may not be exercised prior to the time
the Mid-point price is determined unless the Mid-point price is not determined
within four months of the Date of Grant, in which case the Warrant may be
exercised after such four month period whether or not the Mid-point price has
been determined. If the Mid-point price has not been determined, the Warrant
Price shall be $18.24.

     2.   METHOD OF EXERCISE; PAYMENT; ISSUANCE OF NEW WARRANT. Subject to
Section 1 hereof, the purchase right represented by this Warrant may be
exercised by the holder hereof, in whole or in part and from time to time, by
the surrender of this Warrant (with the notice of exercise form attached hereto
as EXHIBIT A duly executed) at the principal office of Rackspace and by the
payment to Rackspace, by wire transfer according to wire transfer instructions
provided by Rackspace, of an amount equal to the then applicable Warrant Price
multiplied by the number of Shares then being purchased. The entity or entities
in whose name(s) any certificate(s) representing Shares shall be issuable upon
exercise of this Warrant shall be deemed to have become the holder(s) of record
of, and shall be treated for all purposes


                                       -1-
<PAGE>

as the record holder(s) of, the units or shares represented thereby (and such
units or shares shall be deemed to have been issued) immediately prior to the
close of business on the date or dates upon which this Warrant is exercised. In
the event of any exercise of the rights represented by this Warrant,
certificates for the units or shares of stock so purchased shall be delivered to
the holder hereof as soon as possible and in any event within thirty days after
such exercise and, unless this Warrant has been fully exercised or expired, a
new Warrant representing the portion of the Shares, if any, with respect to
which this Warrant shall not then have been exercised shall also be issued to
the holder hereof as soon as possible and in any event within such thirty day
period.

     3. STOCK FULLY PAID. All Shares that may be issued upon the exercise of the
rights represented by this Warrant will, upon issuance pursuant to the terms and
conditions herein, be fully paid and nonassessable, and free from all taxes,
liens and charges with respect to the issue thereof.

     4. ADJUSTMENT OF WARRANT PRICE AND NUMBER OF SHARES. The number and kind of
securities purchasable upon the exercise of this Warrant and the Warrant Price
shall be subject to adjustment from time to time upon the occurrence of certain
events, as follows:

          (a) RECLASSIFICATION OR MERGER. In case of any reclassification,
change or conversion of securities of the class issuable upon exercise of this
Warrant (other than a change in par value, or from par value to no par value, or
from no par value to par value, or as a result of a subdivision or combination),
or in case of any merger of Rackspace with or into another corporation (other
than a merger with another corporation in which Rackspace is the acquiring and
the surviving corporation and which does not result in any reclassification or
change of outstanding securities issuable upon exercise of this Warrant), or in
case of any sale of all or substantially all of the assets of Rackspace, or such
successor or purchasing corporation, as the case may be, or its parent
corporation, shall duly execute and deliver to the holder of this Warrant a new
Warrant (in form and substance reasonably satisfactory to the holder of this
Warrant), so that the holder of this Warrant shall have the right to receive, at
a total purchase price not to exceed that payable upon the exercise of the
unexercised portion of this Warrant, and in lieu of the Shares theretofore
issuable upon exercise of this Warrant, the kind and amount of shares of stock,
other securities, money and property receivable upon such reclassification,
change or merger by a holder of the number of Shares then purchasable under this
Warrant. Such new Warrant shall provide for adjustments that shall be as nearly
equivalent as may be practicable to the adjustments provided for in this Section
4. The provisions of this subparagraph (a) shall similarly apply to successive
reclassifications, changes, mergers, consolidations, transfers, amendments and
waivers.

          (b) SUBDIVISION OR COMBINATION OF SHARES. If Rackspace at any time
while this Warrant remains outstanding and unexpired shall subdivide or combine
its outstanding Shares, the Warrant Price shall be proportionately decreased in
the case of a subdivision or increased in the case of a combination, effective
at the close of business on the date the subdivision or combination becomes
effective.

          (c) STOCK DIVIDENDS AND OTHER DISTRIBUTIONS/CAPITAL ACCOUNT UPON
EXERCISE OF OPTION. In case Rackspace shall make or issue, or shall fix a record
date for the determination of eligible holders entitled to receive, a dividend
or other distribution with respect to the Shares (or any shares of stock or
other securities at the time issuable upon exercise of the Warrant) payable in
(a) securities of


<PAGE>

Rackspace or (b) assets (excluding cash dividends paid or payable solely out of
retained earnings), then, in each such case, the holder of this Warrant on
exercise hereof at any time after the consummation, effective date or record
date of such dividend or other distribution, shall receive, in addition to the
Shares (or such other stock or securities) issuable on such exercise prior to
such date, and without the payment of additional consideration therefor, the
securities or such other assets of Rackspace to which such Holder would have
been entitled upon such date if such Holder had exercised this Warrant on the
date hereof and had thereafter, during the period from the date hereof to and
including the date of such exercise, retained such shares and/or all other
additional stock available by it as aforesaid during such period giving effect
to all adjustments called for by this Section 4. Units issued upon exercise of
the Warrant shall be issued with a capital account (provided that Rackspace upon
such exercise is a partnership or other entity for which capital accounts are
maintained in respect of units of ownership) which shall bear the same ratio to
the total capital accounts in Rackspace as the number of such Units issued upon
exercise bear to the aggregate units of ownership in the Company then
outstanding.

          (d) ADJUSTMENT OF NUMBER OF SHARES. Upon each adjustment in the
Warrant Price, the number of Shares purchasable hereunder shall be adjusted, to
the nearest whole share, to the product obtained by multiplying the number of
Shares purchasable immediately prior to such adjustment in the Warrant Price by
a fraction, the numerator of which shall be the Warrant Price immediately prior
to such adjustment and the denominator of which shall be the Warrant Price
immediately thereafter.

          (e) CONVERSION OF SHARES. In the event that all of the authorized and
outstanding Shares are redeemed or converted or reclassified into other
securities or property pursuant to Rackspace's charter documents or otherwise,
or the Shares otherwise cease to exist, then, in such case, the Holder of this
Warrant, upon exercise hereof at any time after the date on which the Shares are
so redeemed or converted, reclassified or cease to exist (the "Termination
Date"), shall receive, in lieu of the number of Shares that would have been
issuable upon such exercise immediately prior to the Termination Date, the
securities or property that would have been received if this Warrant had been
exercised in full and the Shares received thereupon had been simultaneously
converted immediately prior to the Termination Date, all subject to further
adjustment as provided in this Warrant. Additionally, the Warrant Price shall be
immediately adjusted to equal the quotient obtained by dividing (x) the
aggregate Warrant Price of the maximum number of Shares for which this Warrant
was exercisable immediately prior to the Termination Date by (y) the number of
Shares for which this Warrant is exercisable immediately after the Termination
Date, all subject to further adjustment as provided herein.

     5. NOTICE OF ADJUSTMENTS. Whenever the Warrant Price or the number of
Shares purchasable hereunder shall be adjusted pursuant to Section 4 hereof,
Rackspace shall make a certificate signed by its chief executive officer setting
forth, in reasonable detail, the event requiring the adjustment, the amount of
the adjustment, the method by which such adjustment was calculated, and the
Warrant Price and the number of Shares purchasable hereunder after giving effect
to such adjustment, which shall be mailed (by first class mail, postage prepaid)
to the holder of this Warrant.

     6. FRACTIONAL SHARES. No fractional Shares will be issued in connection
with any exercise hereunder, but in lieu of such fractional Shares Rackspace
shall make a cash payment therefor based on the fair market value of the Shares
on the date of exercise as reasonably determined in good faith by Rackspace's
Board of Directors.
<PAGE>

     7. COMPLIANCE WITH SECURITIES ACT: DISPOSITION OF WARRANT OR SHARES.

          (a) COMPLIANCE WITH SECURITIES ACT. The holder of this Warrant, by
acceptance hereof, agrees that this Warrant, and the Shares to be issued upon
exercise hereof are being acquired for investment and that such holder will not
offer, sell or otherwise dispose of this Warrant, or any Shares to be issued
upon exercise hereof except under circumstances which will not result in a
violation of the Securities Act of 1933, as amended (the "Act"). If at the time
of any transfer or exercise of this Warrant or any of the Shares, such
securities have not been registered under the Act and are not eligible for sale
without registration under Rule 144 of the Act, Rackspace may require as a
condition of allowing such transfer or exercise, that the holder of such
securities furnish to Rackspace such information as is reasonably necessary to
establish that such transfer and exercise may be made without registration under
the Act. This Warrant and all Shares issued upon exercise of this Warrant
(unless registered under the Act) shall be stamped or imprinted with a legend in
substantially the following form:

     "THE SECURITIES EVIDENCED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE SECURITIES LAWS. NO SALE OR
DISPOSITION MAY BE EFFECTED WITHOUT (i) EFFECTIVE REGISTRATION STATEMENTS
RELATED THERETO, (ii) AN OPINION OF COUNSEL FOR THE HOLDER, REASONABLY
SATISFACTORY TO RACKSPACE, THAT SUCH REGISTRATIONS ARE NOT REQUIRED OR (iii)
RECEIPT OF NO-ACTION LETTERS FROM THE APPROPRIATE GOVERNMENTAL AUTHORITIES. IN
ADDITION, NO SALE OR DISPOSITION MAY BE EFFECTED WITHOUT COMPLYING WITH THE
PROVISIONS OF SECTION 7 OF THE WARRANT UNDER WHICH THESE SECURITIES WERE ISSUED,
DIRECTLY OR INDIRECTLY."


          (b) DISPOSITION OF WARRANT OR SHARES. Subject to the provisions of
this Section 7, this Warrant may be assigned or transferred in whole or in part
by the holder hereof. With respect to any proposed offer, sale or other
disposition of this Warrant or any Shares acquired pursuant to the exercise of
this Warrant prior to registration of such Warrant or shares, the holder hereof
and each subsequent holder of this Warrant agrees to seek and obtain the written
permission of Rackspace prior thereto, describing briefly the manner thereof,
together with a written opinion of such holder's counsel, if reasonably
requested by Rackspace, to the effect that such offer, sale or other disposition
may be effected without registration or qualification (under the Act as then in
effect or any federal or state law then in effect) of this Warrant or such
Shares and indicating whether or not under the Act certificates for this Warrant
or such Shares to be sold or otherwise disposed of require any restrictive
legend as to applicable restrictions on transferability in order to ensure
compliance with such law. Upon receiving such written notice and reasonably
satisfactory opinion, if so requested, Rackspace, as promptly as practicable,
shall notify such holder whether or not such holder may sell or otherwise
dispose of this Warrant or such Shares, all in accordance with the terms of the
notice delivered to Rackspace. Any offer, sale or other disposition of this
Warrant (or any Shares acquired pursuant to the exercise of this Warrant)
without the prior written consent of Rackspace pursuant to this Section 7(b)
shall be null and void and of no effect.

     8. RIGHTS AS STOCKHOLDERS; INFORMATION. No holder of this Warrant, as such,
shall be entitled to vote or receive dividends or be deemed the holder of Shares
or any other securities of Rackspace
<PAGE>

which may at any time be issuable on the exercise hereof for any purpose, nor
shall anything contained herein be construed to confer upon the holder of this
Warrant, as such, any of the rights of a partner or stockholder of Rackspace or
any right to vote for the election of directors or upon any matter submitted to
stockholders or partners at any meeting thereof, or to receive notice of
meetings, or to receive dividends or subscription rights or otherwise until this
Warrant shall have been exercised and the Shares purchasable upon the exercise
hereof shall have become deliverable, as provided herein.

     9. MODIFICATION AND WAIVER. This Warrant and any provision hereof may be
changed, waived, discharged or terminated only by an instrument in writing
signed by the party against which enforcement of the same is sought.

     10. NOTICES. Any notice, request, communication or other document required
or permitted to be given or delivered to the holder hereof or Rackspace shall be
delivered, or shall be sent by certified or registered mail, postage prepaid, to
each such holder at its address as shown on the books of Rackspace or to
Rackspace at the address indicated therefor on the signature page of this
Warrant.

     11. BINDING EFFECT ON SUCCESSORS. Until the issuance of any new warrant
required to be issued under Section 4(a), this Warrant shall be binding upon any
corporation that issues securities in exchange for securities of the class
issuable upon exercise of this Warrant in connection with any merger,
consolidation or acquisition of all or substantially all of Rackspace's assets,
and all of the obligations of Rackspace relating to the Shares issuable upon the
exercise of this Warrant shall survive the exercise and termination of this
Warrant and all of the covenants and agreements of Rackspace shall inure to the
benefit of the successors and assigns of the holder hereof. Rackspace will, at
the time of the exercise of this Warrant, in whole or in part, upon request of
the holder hereof but at Rackspace's expense, acknowledge in writing its
continuing obligation to the holder hereof in respect of any rights (including,
without limitation, any right to registration of the shares) to which the holder
hereof shall continue to be entitled after such exercise or conversion in
accordance with this Warrant; provided, that the failure of the holder hereof to
make any such request shall not affect the continuing obligation of Rackspace to
the holder hereof in respect of such rights.

     12. LOST WARRANTS OR STOCK CERTIFICATES. Rackspace covenants to the holder
hereof that, upon receipt of evidence reasonably satisfactory to Rackspace of
the loss, theft, destruction or mutilation of this Warrant or any stock
certificate and, in the case of any such loss, theft or destruction, upon
receipt of an indemnity reasonably satisfactory to Rackspace, or in the case of
any such mutilation upon surrender and cancellation of such Warrant or stock
certificate, Rackspace will make and deliver a new Warrant or stock certificate,
of like tenor, in lieu of the lost, stolen, destroyed or mutilated Warrant or
stock certificate.

     13. DESCRIPTIVE HEADINGS. The descriptive headings of the several
paragraphs of this Warrant are inserted for convenience only and do not
constitute a part of this Warrant.

     14. GOVERNING LAW. This Warrant shall be construed and enforced in
accordance with, and the rights of the parties shall be governed by, the
internal laws of the State of Texas without regard to its conflicts of laws
principles.
<PAGE>

     15. SURVIVAL. All agreements of Rackspace and the holder hereof contained
herein shall survive indefinitely until, by their respective terms, they are no
longer operative.

     16. REMEDIES. In case any one or more of the covenants and agreements
contained in this Warrant shall have been breached, the holders hereof (in the
case of a breach by Rackspace), or Rackspace (in the case of a breach by a
holder), may proceed to protect and enforce their or its rights either by suit
in equity and/or by action at law, including, but not limited to, an action for
damages as a result of any such breach and/or an action for specific performance
of any such covenant or agreement contained in this Warrant.

     17. ACCEPTANCE. Receipt of this Warrant by the holder hereof shall
constitute acceptance of and agreement to the foregoing terms and conditions.

     18. NO IMPAIRMENT OF RIGHTS. Rackspace will not, by amendment of its
charter documents through any other means, avoid or seek to avoid the observance
or performance of any of the terms of this Warrant, but will at all times in
good faith assist in the carrying out of all such terms and in the taking of all
such action as may be necessary or appropriate in order to protect the rights of
the holder of this Warrant against impairment. Without limiting the generality
of the foregoing, Rackspace (a) will not increase the par value of any shares of
stock issuable upon the exercise of this Warrant above the amount payable
therefor upon such exercise, and (b) will take all such action as may be
necessary or appropriate in order that Rackspace may validly and legally issue
fully paid and non-assessable Shares upon exercise of this Warrant.

     19. SEVERABILITY. If any term, provision, covenant, or restriction of this
Warrant is held by a court of competent jurisdiction to be invalid, void or
unenforceable, the remainder of the terms, provisions, covenants and
restrictions of this Warrant shall remain in full force and effect and shall in
no way be affected, impaired or invalidated.

     20. NOTICES OF RECORD DATE. In case:

         (a) Rackspace shall take a record of the holders of its securities, for
the purpose of entitling them to receive any dividend or other distribution, or
any right to subscribe for or purchase any shares of stock of any class or any
other securities or to receive any other right; or

         (b) of any consolidation or merger of Rackspace with or into another
corporation, any capital reorganization of Rackspace, any reclassification of
the capital stock of Rackspace, or any conveyance of all or substantially all of
the assets of Rackspace to another corporation in which holders of Rackspace's
stock are to receive stock, securities or property of another corporation; or

         (c) of any voluntary dissolution, liquidation or winding-up of
Rackspace; or

         (d) of any redemption or conversion of all outstanding securities.

Then, and in each such case, Rackspace will mail or cause to be mailed to the
holder of this Warrant a notice specifying, as the case may be, (i) the date on
which a record is to be taken for the purpose of such dividend, distribution or
right, or (ii) the date on which such reorganization, reclassification,
<PAGE>

consolidation, merger, conveyance, dissolution, liquidation, winding-up,
redemption or conversion is to take place, and the time, if any is to be fixed,
as of which the holders of record of Rackspace's shares or units (or such stock
or securities as at the time are receivable upon the exercise of this Warrant)
shall be entitled to exchange their shares or units (or such other stock or
securities), for securities or other property deliverable upon such
reorganization, reclassification, consolidation, merger, conveyance,
dissolution, liquidation or winding-up. Such notice shall be delivered at least
seven (7) days prior to the date therein specified.
<PAGE>

                                      RACKSPACE, LTD.

                                      By:  Macroweb, LC, its general partner

                                      By:  /s/ Graham Weston
                                          -------------------------------------
                                            Graham Weston, CEO

ACKNOWLEDGED AND AGREED:

/s/ George Still, Jr.
---------------------------------
Signature

Norwest Venture Partners
---------------------------------
Name of Holder
<PAGE>

                                    EXHIBIT A

                               NOTICE OF EXERCISE

To:      RACKSPACE, LTD.

         1.       The undersigned hereby elects to purchase _________________
units or shares of ________________ of RACKSPACE, LTD. pursuant to the terms of
the attached Warrant, and tenders herewith payment of the purchase price of such
shares in full.

         2.       Please issue a certificate or certificates representing said
shares in the name of the undersigned or in such other name or names as are
specified below:



                          -----------------------------
                                     (Name)



                          -----------------------------

                          -----------------------------
                                    (Address)

         3.       The undersigned represents that the aforesaid shares are being
acquired for the account of the undersigned for investment and not with a view
to, or for resale in connection with, the distribution thereof and that the
undersigned has no present intention of distributing or reselling such shares.
In support thereof, the undersigned has executed an Investment Representation
Statement attached hereto as Schedule 1.

                                      -----------------------------------------
                                      Signature

                                      -----------------------------------------
                                      Date
<PAGE>

Schedule 1
----------

INVESTMENT REPRESENTATION STATEMENT

Purchaser:
            --------------------------------

Rackspace:  RACKSPACE, LTD. ("Rackspace")

Security:
            --------------------------------

Amount:
            --------------------------------

Date:
            --------------------------------

         In connection with the purchase of the above-listed securities (the
"Securities"), the undersigned (the "Purchaser") represents to Rackspace as
follows:

         (a)      The Purchaser is aware of Rackspace's business affairs and
financial condition, and has acquired sufficient information about Rackspace to
reach an informed and knowledgeable decision to acquire the Securities. The
Purchaser is purchasing the Securities for its own account for investment
purposes only and not with a view to, or for the resale in connection with, any
"distribution" thereof for purposes of the Securities Act of 1933, as amended
(the "Act").

         (b)      The Purchaser understands that the Securities have not been
registered under the Securities Act in reliance upon a specific exemption
therefrom, which exemption depends upon, among other things, the bona fide
nature of the Purchaser's investment intent as expressed herein. In this
connection, the Purchaser understands that, in the view of the Securities and
Exchange Commission ("SEC"), the statutory basis for such exemption may be
unavailable if the Purchaser's representation was predicated solely upon a
present intention to hold these Securities for the minimum capital gains period
specified under tax statutes, for a deferred sale, for or until an increase or
decrease in the market price of the Securities, or for a period of one year or
any other fixed period in the future.

         (c)      The Purchaser further understands that the Securities must be
held indefinitely unless subsequently registered under the Act or unless an
exemption from registration is otherwise available. Moreover, the Purchaser
understands that Rackspace is under no obligation to register the Securities
except as set forth in the Warrant under which the Securities are being
acquired. In addition, the Purchaser understands that the certificate evidencing
the Securities will be imprinted with the legend referred to in the Warrant
under which the Securities are being purchased.

         (d)      The Purchaser is aware of the provisions of Rule 144 and 144A,
promulgated under the Act, which, in substance, permit limited public resale of
"restricted securities" acquired, directly or indirectly, from the issuer
thereof (or from an affiliate of such issuer), in a non-public offering subject
to the satisfaction of certain conditions, if applicable, including, among other
things: The availability of certain public information about Rackspace, the
resale occurring not less than one year after the party has purchased and paid
for the securities to be sold; the sale being made through a broker in an
unsolicited "broker's transaction" or in transactions directly with a market
maker (as said term is defined
<PAGE>

under the Securities Exchange Act of 1934, as amended) and the amount of
securities being sold during any three-month period not exceeding the specified
limitations stated therein.

         (e)      The Purchaser further understands that at the time it wishes
to sell the Securities there may be no public market upon which to make such a
sale, and that, even if such a public market then exists, Rackspace may not be
satisfying the current public information requirements of Rule 144 and 144A, and
that, in such event, the Purchaser may be precluded from selling the Securities
under Rule 144 and 144A even if the one-year minimum holding period had been
satisfied.

         (f)      The Purchaser further understands that in the event all of the
requirements of Rule 144 and 144A are not satisfied, registration under the Act,
compliance with Regulation A, or some other registration exemption will be
required; and that, notwithstanding the fact that Rule 144 is not exclusive, the
Staff of the SEC has expressed its opinion that persons proposing to sell
private placement securities other than in a registered offering and otherwise
than pursuant to Rule 144 will have a substantial burden of proof in
establishing that an exemption from registration is available for such offers or
sales, and that such persons and their respective brokers who participate in
such transactions do so at their own risk.

                                        Purchaser:




                                        Date:
                                               ---------------, ----

                                      -2-