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                                                                     EXHIBIT 4.9

                                                               EXECUTION VERSION

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                           IRON MOUNTAIN INCORPORATED

                           THE GUARANTORS NAMED HEREIN

                                       AND

                              THE BANK OF NEW YORK,
                                   as Trustee


                    6-5/8% Senior Subordinated Notes due 2016


                          SECOND SUPPLEMENTAL INDENTURE


                            Dated as of June 20, 2003


                                       TO


                           SUBORDINATED DEBT INDENTURE


                          Dated as of December 30, 2002


================================================================================

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                                TABLE OF CONTENTS

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ARTICLE 1. DEFINITIONS................................................................................1

   Section 1.1.    DEFINITIONS........................................................................1

ARTICLE 2. FORM AND TERMS OF THE NOTES...............................................................15

   Section 2.1.    FORM AND DATING...................................................................15
   Section 2.2.    EXECUTION AND AUTHENTICATION......................................................16
   Section 2.3.    DEPOSITORY AND PAYING AGENT FOR NOTES.............................................16
   Section 2.4.    TRANSFER AND EXCHANGE OF NOTES....................................................16
   Section 2.5.    REDEMPTION........................................................................18
   Section 2.6.    COVENANTS.........................................................................21
      (a)     Restricted Payments....................................................................21
      (b)     Incurrence of Indebtedness and Issuance of Preferred Stock.............................24
      (c)     Liens..................................................................................25
      (d)     Dividend and Other Payment Restrictions Affecting Restricted Subsidiaries..............25
      (e)     Transactions with Affiliates...........................................................26
      (f)     Certain Senior Subordinated Debt.......................................................27
      (g)     Additional Subsidiary Guarantees.......................................................27
      (h)     Designation of Unrestricted Subsidiaries...............................................28
      (i)     Limitation on Sale and Leaseback Transactions..........................................29
      (j)     Asset Sales............................................................................30
      (k)     Change of Control Offer................................................................32
   Section 2.7.    SUBSIDIARY GUARANTEES.............................................................33
   Section 2.8.    LEGAL DEFEASANCE AND COVENANT DEFEASANCE..........................................33
   Section 2.9.    SUBORDINATION.....................................................................34

ARTICLE 3. MISCELLANEOUS.............................................................................34

   Section 3.1.    EFFECT OF HEADINGS................................................................34
   Section 3.2.    SUCCESSORS AND ASSIGNS............................................................34
   Section 3.3.    SEPARABILITY CLAUSE...............................................................34
   Section 3.4.    GOVERNING LAW.....................................................................34
   Section 3.5.    FIRST SUPPLEMENT TO SUPERSEDE INDENTURE...........................................34
</Table>


EXHIBITS

Exhibit A         FORM OF NOTES
Exhibit B         FORM OF SUPPLEMENTAL INDENTURE

                                        i
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               THIS SECOND SUPPLEMENTAL INDENTURE, dated as of June 20, 2003
("SECOND SUPPLEMENTAL INDENTURE"), is by and between IRON MOUNTAIN INCORPORATED,
a Pennsylvania corporation (the "COMPANY"), having its principal office at 745
Atlantic Avenue, Boston, Massachusetts 02111, the Guarantors signatory hereto,
and THE BANK OF NEW YORK, a New York banking corporation, as trustee (the
"TRUSTEE"), having its principal corporate trust office at 101 Barclay Street, 8
Floor West, New York, NY 10286.

                                   WITNESSETH:

               WHEREAS, the Company and The Bank of New York, acting as trustee,
executed and delivered a Subordinated Indenture, dated as of December 30, 2002
(the "INDENTURE"), to provide for the issuance by the Company from time to time
of Securities to be issued in one or more series as provided in the Indenture;

               WHEREAS, the issuance and sale of up to $250,000,000 aggregate
principal amount of a series of the Company's Securities (the "NOTES") have been
authorized by resolutions adopted by the Executive Committee of the Board of
Directors of the Company on June 16, 2003;

               WHEREAS, the Company desires to issue and sell $150,000,000
aggregate principal amount of the Notes on the date hereof;

               WHEREAS, the Company desires to enter into this Second
Supplemental Indenture pursuant to Section 9.1(e) of the Indenture to supplement
the Indenture to establish the form and terms of the Notes; and

               NOW, THEREFORE, for and in consideration of the premises stated
herein and the purchase of the Notes by the Holders thereof, the parties hereto
hereby enter into this Second Supplemental Indenture, for the equal and
proportionate benefit of all Holders of Notes, as follows:

                                   ARTICLE 1.

                                   DEFINITIONS

Section 1.1.   DEFINITIONS.

               (a)    All of the terms used in this Second Supplemental
Indenture that are defined in the Indenture shall have the meanings specified in
the Indenture, unless otherwise defined herein (in which case they shall have
the meanings defined herein for the purposes of the Indenture as well as for the
Second Supplemental Indenture) or unless the context otherwise requires, and for
the purposes of this Second Supplemental Indenture, the following terms have the
meanings set forth in this Section:

               "ACQUIRED DEBT" means, with respect to any specified Person:

               (1)    Indebtedness of any other Person, existing at the time
                      such other Person merged with or into or became a
                      Subsidiary of such specified Person, including
                      Indebtedness incurred in connection with, or in
                      contemplation of, such other Person merging with or into
                      or becoming a Subsidiary of such specified Person; and

               (2)    Indebtedness encumbering any asset acquired by such
                      specified Person.

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               "ACQUISITION EBITDA" means, as of any date of determination, with
respect to an Acquisition EBITDA Entity, the sum of:

               (1)    EBITDA of such Acquisition EBITDA Entity for its last
                      fiscal quarter for which financial statements are
                      available at such date of determination (adjusted to give
                      pro forma effect to any acquisition or disposition of a
                      business or Person by such Acquisition EBITDA Entity
                      consummated during the period covered by, or after the
                      date of, such quarterly financial statements), multiplied
                      by four (or if such quarterly statements are not
                      available, EBITDA for the most recent fiscal year for
                      which financial statements are available), plus

               (2)    projected quantifiable improvements in operating results
                      (on an annualized basis) due to cost reductions calculated
                      in good faith by the Company or one of its Restricted
                      Subsidiaries, as certified by an Officers' Certificate
                      filed with the Trustee, without giving effect to any
                      operating losses of the acquired Person.

               "ACQUISITION EBITDA ENTITY" means, as of any date of
determination, a business or Person:

               (1)    which has been acquired by the Company or one of its
                      Restricted Subsidiaries and with respect to which
                      financial results on a consolidated basis with the Company
                      have not been made available for an entire fiscal quarter;
                      or

               (2)    which is to be acquired in whole or in part with
                      Indebtedness, the incurrence of which will require the
                      calculation on such date of the Acquisition EBITDA of such
                      Acquisition EBITDA Entity for purposes of Section 2.6(b)
                      of this Second Supplemental Indenture (Section 4.9 of the
                      Indenture).

               "ADDITIONAL NOTES" means such amount of the Company's 6-5/8%
Senior Subordinated Notes due 2016 (other than the Initial Notes) as the Company
may issue from time to time under this Second Supplemental Indenture in
accordance with Section 2.2 hereof as part of the same series as the Initial
Notes.

               "ADJUSTED EBITDA" means, as of any date of determination and
without duplication, the sum of:

               (1)    EBITDA of the Company and its Restricted Subsidiaries for
                      the most recent fiscal quarter for which internal
                      financial statements are available at such date of
                      determination, multiplied by four; and

               (2)    Acquisition EBITDA of each business or Person that is an
                      Acquisition EBITDA Entity as of such date of
                      determination, multiplied by a fraction, (i) the numerator
                      of which is three minus the number of months (and/or any
                      portion thereof) in such most recent fiscal quarter for
                      which the financial results of such Acquisition EBITDA
                      Entity are included in the EBITDA of the Company and its
                      Restricted Subsidiaries under clause (1) above, and (ii)
                      the denominator of which is three. The effects of unusual
                      items, including merger-related expenses permitted to be
                      shown as a separate line item on a statement of operations
                      in accordance with GAAP, or non-recurring items in respect
                      of the Company, a Restricted

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                      Subsidiary or an Acquisition EBITDA Entity occurring in
                      any period shall be excluded in the calculation of
                      Adjusted EBITDA.

               "AGENT MEMBERS" means members of, or participants in, the
               Depository.

               "ATTRIBUTABLE INDEBTEDNESS" in respect of a Sale and Leaseback
Transaction means, as of the time of determination, the greater of:

               (1)    the fair market value of the property subject to such
                      arrangement (as determined by the Board of Directors of
                      the Company); and

               (2)    the present value (discounted at the rate of interest
                      implicit in such transaction) of the total obligations of
                      the lessee for rental payments during the remaining terms
                      of the lease included in such Sale and Leaseback
                      Transaction (including any period for which such lease has
                      been extended).

               "CANADA COMPANY" means Iron Mountain Canada Corporation, a Wholly
Owned Subsidiary of the Company, formerly known as Pierce Leahy Canada Company.

               "CASH EQUIVALENTS" means:

               (1)    securities with maturities of one year or less from the
                      date of acquisition, issued, fully guaranteed or insured
                      by the United States Government or any agency thereof;

               (2)    certificates of deposit, time deposits, overnight bank
                      deposits, bankers acceptances and repurchase agreements
                      issued by a Qualified Issuer having maturities of 270 days
                      or less from the date of acquisition;

               (3)    commercial paper of an issuer rated at least A-2 by
                      Standard & Poor's Rating Group, a division of McGraw Hill,
                      Inc., or P-2 by Moody's Investors Service, or carrying an
                      equivalent rating by a nationally recognized rating agency
                      if both of the two named rating agencies cease publishing
                      ratings of investments and having maturities of 270 days
                      or less from the date of acquisition;

               (4)    money market accounts or funds with or issued by Qualified
                      Issuers; and

               (5)    Investments in money market funds substantially all of the
                      assets of which are comprised of securities and other
                      obligations of the types described in clauses (1) through
                      (3) above.

               "CHANGE OF CONTROL" means the occurrence of any of the following
events:

               (1)    any "person" or "group" (as such terms are used in
                      Sections 13(d) and 14(d) of the Exchange Act), other than
                      the Principal Stockholders (or any of them), is or becomes
                      the "beneficial owner" (as defined in Rules 13d-3 and
                      13d-5 under the Exchange Act), directly or indirectly, of
                      more than a majority of the voting power of all classes of
                      Voting Stock of the Company;

               (2)    the Company consolidates with, or merges with or into,
                      another Person or conveys, transfers, leases or otherwise
                      disposes of all or substantially all of its

                                        3
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                      assets to any Person, or any Person consolidates with,
                      or merges with or into, the Company, in any such event
                      pursuant to a transaction in which the outstanding Voting
                      Stock of the Company is converted into or exchanged for
                      cash, securities or other property, other than any such
                      transaction where (i) the outstanding Voting Stock of the
                      Company is not converted or exchanged at all (except to
                      the extent necessary to reflect a change in the
                      jurisdiction of incorporation) or is converted into or
                      exchanged for (A) Voting Stock (other than Disqualified
                      Stock) of the surviving or transferee Person or (B) cash,
                      securities and other property (other than Capital Stock
                      described in the foregoing clause (A)) of the surviving or
                      transferee Person in an amount that could be paid as a
                      Restricted Payment pursuant to Section 2.6(a) of the
                      Second Supplemental Indenture (Section 4.8 of the
                      Indenture) and (ii) immediately after such transaction, no
                      "person" or "group" (as such terms are used in Sections
                      13(d) and 14(d) of the Exchange Act), other than the
                      Principal Stockholders (or any of them), is the
                      "beneficial owner" (as defined in Rules 13d-3 and 13d-5
                      under the Exchange Act), directly or indirectly, of more
                      than a majority of the total outstanding Voting Stock of
                      the surviving or transferee Person;

               (3)    during any consecutive two-year period, individuals who at
                      the beginning of such period constituted the Board of
                      Directors (together with any new directors whose election
                      to such Board of Directors, or whose nomination for
                      election by the stockholders of the Company, was approved
                      by a vote of 66 2/3% of the directors then still in office
                      who were either directors at the beginning of such period
                      or whose election or nomination for election was
                      previously so approved) cease for any reason to constitute
                      a majority of the Board of Directors then in office; or

               (4)    the Company is liquidated or dissolved or adopts a plan of
                      liquidation or dissolution other than in a transaction
                      which complies with Section 5.1 of the Indenture.

               "CONSOLIDATED ADJUSTED NET INCOME" means, for any period, the net
income (or net loss) of the Company and its Restricted Subsidiaries for such
period as determined on a consolidated basis in accordance with GAAP, adjusted
to the extent included in calculating such net income or loss by excluding:

               (1)    any net after-tax extraordinary gains or losses (less all
                      fees and expenses relating thereto);

               (2)    any net after-tax gains or losses (less all fees and
                      expenses relating thereto) attributable to Asset Sales;

               (3)    the portion of net income (or loss) of any Person (other
                      than the Company or a Restricted Subsidiary), including
                      Unrestricted Subsidiaries, in which the Company or any
                      Restricted Subsidiary has an ownership interest, except to
                      the extent of the amount of dividends or other
                      distributions actually paid to the Company or any
                      Restricted Subsidiary in cash dividends or distributions
                      by such Person during such period; and

                                        4
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               (4)    the net income (or loss) of any Person combined with the
                      Company or any Restricted Subsidiary on a "pooling of
                      interests" basis attributable to any period prior to the
                      date of combination.

               "CONSOLIDATED INCOME TAX EXPENSE" means, for any period, the
provision for federal, state, local and foreign income taxes of the Company and
its Restricted Subsidiaries for such period as determined on a consolidated
basis in accordance with GAAP.

               "CONSOLIDATED INTEREST EXPENSE" means, for any period, without
duplication, the sum of:

               (1)    the amount which, in conformity with GAAP, would be set
                      forth opposite the caption "interest expense" (or any like
                      caption) on a consolidated statement of operations of the
                      Company and its Restricted Subsidiaries for such period,
                      including, without limitation:

                      (i)     amortization of debt discount;

                      (ii)    the net cost of interest rate contracts (including
                              amortization of discounts);

                      (iii)   the interest portion of any deferred payment
                              obligation;

                      (iv)    amortization of debt issuance costs; and

                      (v)     the interest component of Capital Lease
                              Obligations of the Company and its Restricted
                              Subsidiaries; plus

               (2)    all interest on any Indebtedness of any other Person
                      guaranteed and paid by the Company or any of its
                      Restricted Subsidiaries;

provided, however, that Consolidated Interest Expense will not include any gain
or loss from extinguishment of debt, including write-off of debt issuance costs.

               "CONSOLIDATED NON-CASH CHARGES" means, for any period, the
aggregate depreciation, amortization and other non-cash expenses of the Company
and its Restricted Subsidiaries (including without limitation any minority
interest) reducing Consolidated Adjusted Net Income for such period, determined
on a consolidated basis in accordance with GAAP (excluding any such non-cash
charge to the extent that it requires an accrual of or reserve for cash charges
for any future period).

               "CREDIT AGENT" means JPMorgan Chase Bank, in its capacity as
administrative agent for the lenders party to the Credit Agreement, or any
successor or successors party thereto.

               "CREDIT AGREEMENT" means that certain Fifth Amended and Restated
Credit Agreement, dated as of March 15, 2002, as amended, among the Company,
Canada Company, the lenders party thereto and the Credit Agent, as amended,
restated, supplemented, modified, renewed, refunded, increased, extended,
replaced or refinanced from time to time.

               "DEFINITIVE NOTES" means Notes that are in the form of the Notes
attached hereto as Exhibit A, that do not include the information called for by
Section 2.15 of the Indenture.

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               "EBITDA" means for any period Consolidated Adjusted Net Income
for such period increased by:

               (1)    Consolidated Interest Expense for such period; plus

               (2)    Consolidated Income Tax Expense for such period; plus

               (3)    Consolidated Non-Cash Charges for such period.

               "EQUITY INTERESTS" means Capital Stock and all warrants, options
or other rights to acquire Capital Stock (but excluding any debt security that
is convertible into, or exchangeable for, Capital Stock).

               "EQUITY PROCEEDS" means:

               (1)    with respect to Equity Interests (or debt securities
                      converted into Equity Interests) issued or sold for cash
                      Dollars, the aggregate amount of such cash Dollars; and

               (2)    with respect to Equity Interests (or debt securities
                      converted into Equity Interests) issued or sold for any
                      consideration other than cash Dollars, the aggregate
                      Market Price thereof computed on the date of the issuance
                      or sale thereof.

               "EXCLUDED RESTRICTED SUBSIDIARY" means any Restricted Subsidiary
organized under the laws of a jurisdiction other than the United States (as
defined in Regulation S under the Securities Act) and that has not delivered a
Subsidiary Guarantee.

               "EXISTING INDEBTEDNESS" means Indebtedness of the Company and its
Subsidiaries (other than under the Credit Agreement) in existence on the date of
the Indenture, until such amounts are repaid.

               "GLOBAL NOTE" means a permanent global Note that contains the
paragraph referred to in Section 2.15.3 of the Indenture and the additional
Schedule of Exchanges of Notes to the form of the Note attached hereto as
Exhibit A, and that is deposited with and registered in the name of the
Depository.

               "INITIAL NOTES" means the first $150,000,000 aggregate principal
amount of 6-5/8% Senior Subordinated Notes due 2016 that are issued under this
Second Supplemental Indenture, as amended or supplemented from time to time
pursuant to the Indenture.

               "INVESTMENTS" means, with respect to any Person, all investments
by such Person in other Persons (including Affiliates) in the forms of loans
(including Guarantees), advances or capital contributions (excluding commission,
travel and similar advances to officers and employees made in the ordinary
course of business), purchases or other acquisitions for consideration of
Indebtedness, Equity Interests or other securities and all other items that are
or would be classified as investments on a balance sheet prepared in accordance
with GAAP.

               "LEVERAGE RATIO" means, at any date, the ratio of:

               (1)    the aggregate principal amount of Indebtedness of the
                      Company and its Restricted Subsidiaries outstanding as of
                      the most recent available quarterly or annual balance
                      sheet, to

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               (2)    Adjusted EBITDA, after giving pro forma effect, without
                      duplication, to

                      (i)     the incurrence, repayment or retirement of any
                              Indebtedness by the Company or its Restricted
                              Subsidiaries since the last day of the most recent
                              full fiscal quarter of the Company;

                      (ii)    if the Leverage Ratio is being determined in
                              connection with the incurrence of Indebtedness by
                              the Company or a Restricted Subsidiary, such
                              Indebtedness; and

                      (iii)   the Indebtedness to be incurred in connection with
                              the acquisition of any Acquisition EBITDA Entity.

               "LIEN" means, with respect to any asset, any mortgage, lien,
pledge, charge, security interest or encumbrance of any kind in respect of such
asset, whether or not filed, recorded or otherwise perfected under applicable
law (including any conditional sale or other title retention agreement, any
lease in the nature thereof, any option or other agreement to sell or give a
security interest in and any filing of or agreement to give any financing
statement under the Uniform Commercial Code, or equivalent statutes, of any
jurisdiction).

               "MAKE-WHOLE AMOUNT" means, with respect to any Note, an amount
equal to the excess, if any, of:

               (1)    the present value of the remaining principal, premium and
                      interest payments that would be payable with respect to
                      such Note if such Note were redeemed on July 1, 2008,
                      computed using a discount rate equal to the Treasury Rate
                      plus 75 basis points, over

               (2)    the outstanding principal amount of such Note.

               "MAKE-WHOLE AVERAGE LIFE" means, with respect to any date of
redemption of Notes, the number of years (calculated to the nearest one-twelfth)
from such redemption date to July 1, 2008.

               "MAKE-WHOLE PRICE" means, with respect to any Note, the greater
of:

               (1)    the sum of the principal amount of and Make-Whole Amount
                      with respect to such Note; and

               (2)    the redemption price of such Note on July 1, 2008.

               "MARKET PRICE" means:

               (1)    with respect to the calculation of Equity Proceeds from
                      the issuance or sale of debt securities which have been
                      converted into Equity Interests, the value received upon
                      the original issuance or sale of such converted debt
                      securities, as determined reasonably and in good faith by
                      the Board of Directors; and

               (2)    with respect to the calculation of Equity Proceeds from
                      the issuance or sale of Equity Interests, the average of
                      the daily closing prices for such Equity Interests for the
                      20 consecutive trading days preceding the date of such
                      computation.

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               The closing price for each day shall be:

               (1)    if such Equity Interests are then listed or admitted to
                      trading on the New York Stock Exchange, the closing price
                      on the NYSE Consolidated Tape (or any successor
                      consolidated tape reporting transactions on the New York
                      Stock Exchange) or, if such composite tape shall not be in
                      use or shall not report transactions in such Equity
                      Interests, or if such Equity Interests shall be listed on
                      a stock exchange other than the New York Stock Exchange
                      (including for this purpose the Nasdaq National Market),
                      the last reported sale price regular way for such day, or
                      in case no such reported sale takes place on such day, the
                      average of the closing bid and asked prices regular way
                      for such day, in each case on the principal national
                      securities exchange on which such Equity Interests are
                      listed or admitted to trading (which shall be the national
                      securities exchange on which the greatest number of such
                      Equity Interests have been traded during such 20
                      consecutive trading days); or

               (2)    if such Equity Interests are not listed or admitted to
                      trading on any such exchange, the average of the closing
                      bid and asked prices thereof in the over-the-counter
                      market as reported by the National Association of
                      Securities Dealers Automated Quotation System or any
                      successor system, or if not included therein, the average
                      of the closing bid and asked prices thereof furnished by
                      two members of the National Association of Securities
                      Dealers selected reasonably and in good faith by the Board
                      of Directors for that purpose. In the absence of one or
                      more such quotations, the Market Price for such Equity
                      Interests shall be determined reasonably and in good faith
                      by the Board of Directors.

               "NET PROCEEDS" means the aggregate cash proceeds received by the
Company or any of its Restricted Subsidiaries in respect of any Asset Sale,
which amount is equal to the excess, if any, of:

               (1)    the cash received by the Company or such Restricted
                      Subsidiary (including any cash payments received by way of
                      deferred payment pursuant to, or monetization of, a note
                      or installment receivable or otherwise, but only as and
                      when received) in connection with such disposition, over

               (2)    the sum of:

                      (i)     the amount of any Indebtedness which is secured by
                              such asset and which is required to be repaid in
                              connection with the disposition thereof; plus

                      (ii)    the reasonable out-of-pocket expenses incurred by
                              the Company or such Restricted Subsidiary, as the
                              case may be, in connection with such disposition
                              or in connection with the transfer of such amount
                              from such Restricted Subsidiary to the Company;
                              plus

                      (iii)   provisions for taxes, including income taxes,
                              attributable to the disposition of such asset or
                              attributable to required prepayments or repayments
                              of Indebtedness with the proceeds thereof; plus

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                      (iv)    if the Company does not first receive a transfer
                              of such amount from the relevant Restricted
                              Subsidiary with respect to the disposition of an
                              asset by such Restricted Subsidiary and such
                              Restricted Subsidiary intends to make such
                              transfer as soon as practicable, the out-of-pocket
                              expenses and taxes that the Company reasonably
                              estimates will be incurred by the Company or such
                              Restricted Subsidiary in connection with such
                              transfer at the time such transfer is expected to
                              be received by the Company (including, without
                              limitation, withholding taxes on the remittance of
                              such amount).

               "NOTES" has the meaning assigned to it in the preamble to this
Second Supplemental Indenture. The Initial Notes and any Additional Notes shall
be treated as a single class for all purposes under this Second Supplemental
Indenture and the Indenture.

               "PERMITTED INVESTMENTS" means:

               (1)    any Investments in the Company or in a Restricted
                      Subsidiary (other than an Excluded Restricted Subsidiary)
                      of the Company, including without limitation the Guarantee
                      of Indebtedness permitted under Section 2.6(b) of the
                      Second Supplemental Indenture (Section 4.9 of the
                      Indenture);

               (2)    any Investments in Cash Equivalents;

               (3)    Investments by the Company or any Restricted Subsidiary of
                      the Company in a Person, if as a result of such
                      Investment;

                      (i)     such Person becomes a Restricted Subsidiary (other
                              than an Excluded Restricted Subsidiary) of the
                              Company; or

                      (ii)    such Person is merged, consolidated or amalgamated
                              with or into, or transfers or conveys
                              substantially all of its assets to, or is
                              liquidated into, the Company or a Restricted
                              Subsidiary (other than an Excluded Restricted
                              Subsidiary) of the Company;

               (4)    Investments in assets (including accounts and notes
                      receivable) owned or used in the ordinary course of
                      business;

               (5)    Investments for any purpose related to the Company's
                      records and information management business (including,
                      without limitation, the Company's confidential destruction
                      and fulfillment businesses) in an aggregate outstanding
                      amount not to exceed $10.0 million; and

               (6)    Investments by the Company or a Restricted Subsidiary
                      (other than an Excluded Restricted Subsidiary) in one or
                      more Excluded Restricted Subsidiaries, the aggregate
                      outstanding amount of which does not exceed 10% of the
                      consolidated assets of the Company and its Restricted
                      Subsidiaries.

               "PERMITTED LIENS" means:

               (1)    Liens existing as of the date of issuance of the Notes;

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               (2)    Liens on property or assets of the Company or any
                      Restricted Subsidiary securing Senior Debt;

               (3)    Liens on any property or assets of a Restricted Subsidiary
                      granted in favor of the Company or any Wholly Owned
                      Restricted Subsidiary;

               (4)    Liens securing the Notes or the Guarantees;

               (5)    any interest or title of a lessor under any Capital Lease
                      Obligation or Sale and Leaseback Transaction so long as
                      the Indebtedness, if any, secured by such Lien does not
                      exceed the principal amount of Indebtedness permitted
                      under Section 2.6(b) of the Second Supplemental Indenture
                      (Section 4.9 of the Indenture);

               (6)    Liens securing Acquired Debt created prior to (and not in
                      connection with or in contemplation of) the incurrence of
                      such Indebtedness by the Company or any Restricted
                      Subsidiary; provided that such Lien does not extend to any
                      property or assets of the Company or any Restricted
                      Subsidiary other than the assets acquired in connection
                      with the incurrence of such Acquired Debt;

               (7)    Liens securing Hedging Obligations permitted to be
                      incurred pursuant to clause (7) of Section 2.6(b) of the
                      Second Supplemental Indenture (clause (7) of Section 4.9
                      of the Indenture);

               (8)    Liens arising from purchase money mortgages and purchase
                      money security interests, or in respect of the
                      construction of property or assets, incurred in the
                      ordinary course of the business of the Company or a
                      Restricted Subsidiary; provided that (i) the related
                      Indebtedness is not secured by any property or assets of
                      the Company or any Restricted Subsidiary other than the
                      property and assets so acquired or constructed and (ii)
                      the Lien securing such Indebtedness is created within 60
                      days of such acquisition or construction;

               (9)    statutory Liens or landlords' and carriers',
                      warehousemen's, mechanics', suppliers', materialmen's,
                      repairmen's or other like Liens arising in the ordinary
                      course of business and with respect to amounts not yet
                      delinquent or being contested in good faith by appropriate
                      proceedings, if a reserve or other appropriate provision,
                      if any, as shall be required in conformity with GAAP shall
                      have been made therefor;

               (10)   Liens for taxes, assessments, government charges or claims
                      with respect to amounts not yet delinquent or that are
                      being contested in good faith by appropriate proceedings
                      diligently conducted, if a reserve or other appropriate
                      provision, if any, as is required in conformity with GAAP
                      has been made therefor;

               (11)   Liens incurred or deposits made to secure the performance
                      of tenders, bids, leases, statutory obligations, surety
                      and appeal bonds, government contracts, performance bonds
                      and other obligations of a like nature incurred in the
                      ordinary course of business (other than contracts for the
                      payment of money);

                                       10
<Page>

               (12)   easements, rights-of-way, restrictions and other similar
                      charges or encumbrances not interfering in any material
                      respect with the business of the Company or any Restricted
                      Subsidiary incurred in the ordinary course of business;

               (13)   Liens arising by reason of any judgment, decree or order
                      of any court so long as such Lien is adequately bonded and
                      any appropriate legal proceedings that may have been duly
                      initiated for the review of such judgment, decree or order
                      shall not have been finally terminated or the period
                      within which such proceedings may be initiated shall not
                      have expired;

               (14)   Liens arising under options or agreements to sell assets;

               (15)   other Liens securing obligations incurred in the ordinary
                      course of business, which obligations do not exceed $10.0
                      million in the aggregate at any one time outstanding; and

               (16)   any extension, renewal or replacement, in whole or in
                      part, of any Lien described in the foregoing clauses (1)
                      through (15); provided that any such extension, renewal or
                      replacement shall not extend to any additional property or
                      assets.

               "PRINCIPAL STOCKHOLDERS" means each of Vincent J. Ryan, Schooner
Capital LLC, C. Richard Reese, Kent P. Dauten, B. Thomas Golisano and their
respective Affiliates.

               "QUALIFIED EQUITY OFFERING" means an offering of Capital Stock,
other than Disqualified Stock, of the Company for Dollars, whether registered or
exempt from registration under the Securities Act.

               "QUALIFIED ISSUER" means:

               (1)    any lender party to the Credit Agreement; or

               (2)    any commercial bank:

                      (i)     which has capital and surplus in excess of
                              $500,000,000; and

                      (ii)    the outstanding short-term debt securities of
                              which are rated at least A-2 by Standard & Poor's
                              Rating Group, a division of McGraw-Hill, Inc. or
                              at least P-2 by Moody's Investors Service, or
                              carry an equivalent rating by a nationally
                              recognized rating agency if both of the two named
                              rating agencies cease publishing ratings of
                              investments.

               "QUALIFYING SALE AND LEASEBACK TRANSACTION" means any Sale and
Leaseback Transaction between the Company or any of its Restricted Subsidiaries
and any bank, insurance company or other lender or investor providing for the
leasing to the Company or such Restricted Subsidiary of any property (real or
personal) which has been or is to be sold or transferred by the Company or such
Restricted Subsidiary to such lender or investor or to any Person to whom funds
have been or are to be advanced by such lender or investor and where the
property in question has been constructed or acquired after the date of the
Second Supplemental Indenture.

                                       11
<Page>

               "REFINANCING INDEBTEDNESS" means new Indebtedness incurred or
given in exchange for, or the proceeds of which are used to repay, redeem,
defease, extend, refinance, renew, replace or refund, other Indebtedness;
provided, however, that:

               (1)    the principal amount of such new Indebtedness shall not
                      exceed the principal amount of Indebtedness so repaid,
                      redeemed, defeased, extended, refinanced, renewed,
                      replaced or refunded (plus the amount of fees, premiums,
                      consent fees, prepayment penalties and expenses incurred
                      in connection therewith);

               (2)    such Refinancing Indebtedness shall have a Weighted
                      Average Life to Maturity equal to or greater than the
                      Weighted Average Life to Maturity of the Indebtedness so
                      repaid, redeemed, defeased, extended, refinanced, renewed,
                      replaced or refunded or shall mature after the maturity
                      date of the Notes;

               (3)    to the extent such Refinancing Indebtedness refinances
                      Indebtedness that has a final maturity date occurring
                      after the initial scheduled maturity date of the Notes,
                      such new Indebtedness shall have a final scheduled
                      maturity not earlier than the final scheduled maturity of
                      the Indebtedness so repaid, redeemed, defeased, extended,
                      refinanced, renewed, replaced or refunded and shall not
                      permit redemption at the option of the holder earlier than
                      the earliest date of redemption at the option of the
                      holder of the Indebtedness so repaid, redeemed, defeased,
                      extended, refinanced, renewed, replaced or refunded;

               (4)    to the extent such Refinancing Indebtedness refinances
                      Indebtedness subordinate to the Notes, such Refinancing
                      Indebtedness shall be subordinated in right of payment to
                      the Notes and to the extent such Refinancing Indebtedness
                      refinances Notes or Indebtedness PARI PASSU with the
                      Notes, such Refinancing Indebtedness shall be PARI PASSU
                      with or subordinated in right of payment to the Notes, in
                      each case on terms at least as favorable to the holders of
                      Notes as those contained in the documentation governing
                      the Indebtedness so repaid, redeemed, defeased, extended,
                      refinanced, renewed, replaced or refunded; and

               (5)    with respect to Refinancing Indebtedness incurred by a
                      Restricted Subsidiary, such Refinancing Indebtedness shall
                      rank no more senior, and shall be at least as
                      subordinated, in right of payment to the Subsidiary
                      Guarantee of such Restricted Subsidiary as the
                      Indebtedness being extended, refinanced, renewed, replaced
                      or refunded.

               "RESTRICTED SUBSIDIARY" means:

               (1)    each direct or indirect Subsidiary of the Company existing
                      on the date of the Second Supplemental Indenture (other
                      than Iron Mountain (Netherlands) B.V. and its subsidiaries
                      (including Iron Mountain Europe Limited), Iron Mountain
                      Cayman Ltd. and its subsidiaries, Iron Mountain Mexico,
                      S.A. de R.L. de C.V. and its subsidiaries, Iron Mountain
                      Assurance Corporation and Upper Providence Venture I,
                      L.P.); and

               (2)    any other direct or indirect Subsidiary of the Company
                      formed, acquired or existing after the date of the Second
                      Supplemental Indenture (including an Excluded Restricted
                      Subsidiary),

                                       12
<Page>

which, in the case of (1) or (2), is not designated by the Board of Directors as
an "Unrestricted Subsidiary."

               "SALE AND LEASEBACK TRANSACTION" means any transaction or series
of related transactions pursuant to which a Person sells or transfers any
property or asset in connection with the leasing, or the resale against
installment payments, of such property or asset to the seller or transferor.

               "SENIOR BANK DEBT" means all Obligations outstanding under or in
connection with the Credit Agreement (including Guarantees of such Obligations
by Subsidiaries of the Company).

               "SENIOR DEBT" means:

               (1)    the Senior Bank Debt; and

               (2)    any other Indebtedness permitted to be incurred by the
                      Company or any Restricted Subsidiary, as the case may be,
                      under the terms of the Second Supplemental Indenture or
                      the Indenture, unless the instrument under which such
                      Indebtedness is incurred expressly provides that it is:

                      (i)     on a parity with or subordinated in right of
                              payment to the Notes; or

                      (ii)    subordinated to Senior Debt on terms substantially
                              similar to those of the Notes.

               Notwithstanding anything to the contrary in the foregoing, Senior
Debt shall not include:

               (1)    any liability for federal, state, local or other taxes
                      owed or owing by the Company;

               (2)    any Indebtedness of the Company to any of its Subsidiaries
                      or other Affiliates;

               (3)    any trade payables; or

               (4)    any Indebtedness that is incurred in violation of the
                      Second Supplemental Indenture or the Indenture, provided
                      that such Indebtedness shall be deemed not to have been
                      incurred in violation of the Second Supplemental Indenture
                      or the Indenture for purposes of this clause (4) if, in
                      the case of any obligations under the Credit Agreement,
                      the holders of such obligations or their agent or
                      representative shall have received a representation from
                      the Company to the effect that the incurrence of such
                      Indebtedness does not violate the provisions of the Second
                      Supplemental Indenture or the Indenture.

               "TREASURY RATE" means, at any time of computation, the yield to
maturity at such time (as compiled by and published in the most recent Federal
Reserve Statistical Release H.15(519), which has become publicly available at
least two business days prior to the date of the redemption notice or, if such
Statistical Release is no longer published, any publicly available source of
similar market data) of United States Treasury securities with a constant
maturity most nearly equal to the Make-Whole Average Life; provided, however,
that if the Make-Whole Average Life is not equal to the constant maturity of the
United States Treasury security for which a weekly average yield is given, the
Treasury Rate shall be obtained by linear interpolation (calculated to the
nearest one-twelfth of a year) from the weekly average yields of United States
Treasury securities for which such yields are given, except that if the
Make-Whole

                                       13
<Page>

Average Life is less than one year, the weekly average yield on actually traded
United States Treasury securities adjusted to a constant maturity of one year
shall be used.

               "UNRESTRICTED SUBSIDIARY" means:

               (1)    any Subsidiary that is designated by the Board of
                      Directors as an Unrestricted Subsidiary in accordance with
                      Section 2.6(h) of the Second Supplemental Indenture
                      (Section 4.15 of the Indenture); and

               (2)    any Subsidiary of an Unrestricted Subsidiary.

               As of the date hereof, the following Subsidiaries of the Company
have been designated as Unrestricted Subsidiaries: Iron Mountain (Netherlands)
B.V. and its subsidiaries (including Iron Mountain Europe Limited), Iron
Mountain Cayman Ltd. and its subsidiaries, Iron Mountain Mexico, S.A. de R.L. de
C.V. and its subsidiaries, Iron Mountain Assurance Corporation and Upper
Providence Venture I, L.P.

               "VOTING STOCK" means any class or classes of Capital Stock
pursuant to which the holders thereof have the general voting power under
ordinary circumstances to elect at least a majority of the board of directors,
managers or trustees of any Person (irrespective of whether or not, at the time,
stock of any other class or classes has, or might have, voting power by reason
of the happening of any contingency).

               "WEIGHTED AVERAGE LIFE TO MATURITY" means, when applied to any
Indebtedness at any date, the number of years obtained by dividing:

               (1)    the sum of the products obtained by multiplying (x) the
                      amount of each then remaining installment, sinking fund,
                      serial maturity or other required payment of principal,
                      including payment at final maturity, in respect thereof,
                      by (y) the number of years (calculated to the nearest
                      one-twelfth) that will elapse between such date and the
                      making of such payment, by

               (2)    the then outstanding principal amount of such
                      Indebtedness.

               "WHOLLY OWNED RESTRICTED SUBSIDIARY" means any Restricted
Subsidiary of the Company all of the outstanding Capital Stock or other
ownership interests of which (other than directors' qualifying shares) shall at
the time be owned by the Company or by one or more Wholly Owned Restricted
Subsidiaries of the Company.

               "1996 INDENTURE DATE" means October 1, 1996.

               "1999 INDENTURE DATE" means April 26, 1999.

               "7 3/4 % NOTES" means the Company's 7 3/4% Senior Subordinated
Notes due 2015 issued pursuant to the Indenture.

               "8 1/8% NOTES" means Canada Company's 8 1/8% Senior Notes due
2008 issued pursuant to the indenture dated as of April 7, 1998, by and among
Canada Company, as issuer, the Company and The Bank of New York, as trustee.

                                       14
<Page>

               "8 1/4% NOTES" means the Company's 8 1/4% Senior Subordinated
Notes due 2011 issued pursuant to the indenture dated April 26, 1999, by and
among the Company, certain of its subsidiaries and The Bank of New York, as
trustee.

               "8 5/8% NOTES" means the Company's Senior Subordinated Notes
due 2013 issued pursuant to the indenture dated April 3, 2001, by and among the
Company, certain of its subsidiaries and The Bank of New York, as trustee.

               (b)    Other Definitions.

               The definitions of the following terms may be found in the
Sections indicated as follows:

<Table>
<Caption>
                      Term                                            Defined in Section
                      <S>                                             <C>
                      "Affiliate Transaction"                         2.6(e)
                      "Asset Sale"                                    2.6(j)
                      "Asset Sale Offer"                              2.6(j)
                      "Change of Control Offer"                       2.6(k)
                      "Change of Control Payment"                     2.6(k)
                      "Change of Control Payment Date"                2.6(k)
                      "Commencement Date"                             2.6(j)
                      "Company"                                       Preamble
                      "DTC"                                           2.3
                      "Excess Proceeds"                               2.6(j)
                      "Second Supplemental Indenture"                 Preamble
                      "Indenture"                                     Recitals
                      "Restricted Payments"                           2.6(a)
                      "Trustee"                                       Preamble
</Table>

                                   ARTICLE 2.

                           FORM AND TERMS OF THE NOTES

Section2.1.    FORM AND DATING. GENERAL. The Notes and the Trustee's
certificate of authentication shall be substantially in the form of Exhibit A
attached hereto. The Notes may have notations, legends or endorsements required
by law, stock exchange rule or usage. Each Note shall be dated the date of its
authentication. The Notes shall be in denominations of $1,000 and integral
multiples thereof.

               The terms and provisions contained in the Notes shall constitute,
and are hereby expressly made, a part of the Second Supplemental Indenture and
the Indenture and the Company, the Guarantors and the Trustee, by their
execution and delivery of the Second Supplemental Indenture and the Indenture
(or in the case of any Guarantor that becomes such after the date hereof, a
supplemental indenture pursuant to Section 2.6(g) of this Second Supplemental
Indenture (Section 4.14 of the Indenture)), expressly agree to such terms and
provisions and to be bound thereby. However, to the extent any provision of any
Note conflicts with the express provisions of the Indenture (as supplemented by
this Second Supplemental Indenture), the provisions of the Indenture shall
govern and be controlling.

               (b)    GLOBAL NOTES. Notes shall be issued initially in the form
of the Global Notes, which shall be deposited on behalf of the purchasers of the
Notes represented thereby with the Depository at its New York office, and
registered in the name of the Depository or a nominee of the Depository, duly

                                       15
<Page>

executed by the Company and authenticated by the Trustee as hereinafter
provided. The aggregate principal amount of the Global Notes may from time to
time be increased or decreased by adjustments made on the records of the Trustee
and the Depository or its nominee as hereinafter provided.

               Each Global Note shall represent such of the outstanding Notes as
shall be specified therein and each shall provide that it represents the
aggregate principal amount of outstanding Notes from time to time endorsed
thereon and that the aggregate amount of outstanding Notes represented thereby
may from time to time be reduced or increased, as appropriate, to reflect
exchanges and redemptions. Any endorsement of a Global Note to reflect the
amount of any increase or decrease in the aggregate principal amount of
outstanding Notes represented thereby shall be made by the Trustee or the
Service Agent, at the direction of the Trustee, in accordance with instructions
given by the Holder thereof as required by Section 2.4 hereof.

               (c)    BOOK-ENTRY PROVISIONS. This Section 2.1(c) shall apply
only to the Global Notes deposited with or on behalf of the Depository.

               The Company shall execute and the Trustee shall, in accordance
with this Section 2.1(c), authenticate and deliver the Global Notes that (i)
shall be registered in the name of the Depository or the nominee of the
Depository and (ii) shall be delivered by the Trustee to the Depository or
pursuant to the Depository's instructions or held by the Service Agent.

               Agent Members shall have no rights either under the Second
Supplemental Indenture or the Indenture with respect to any Global Notes held on
their behalf by the Depository or by the Service Agent or under such Global
Notes, and the Depository may be treated by the Company, the Trustee and any
agent of the Company or the Trustee as the absolute owner of such Global Notes
for all purposes whatsoever.

               (d)    DEFINITIVE NOTES. Notes issued in certificated form shall
be substantially in the form of Exhibit A attached hereto (but without including
the text referred to in Section 2.15.3 of the Indenture). Except as provided in
Section 2.4, owners of beneficial interests in the Global Notes will not be
entitled to receive physical delivery of certificated Securities.

Section 2.2.   EXECUTION AND AUTHENTICATION.

               The Trustee shall, upon a written order of the Company signed by
an Officer, authenticate up to $150,000,000 aggregate principal amount of
Initial Notes and such amount of Additional Notes as the Company may issue from
time to time.

Section 2.3.   DEPOSITORY AND PAYING AGENT FOR NOTES.

               The Company initially appoints The Depository Trust Company
("DTC") to act as Depository with respect to the Global Notes. The Company
initially appoints the Trustee to act as the Registrar, Paying Agent and Service
Agent with respect to the Global Notes.


Section 2.4.   TRANSFER AND EXCHANGE OF NOTES.

               (a)    TRANSFER AND EXCHANGE OF GLOBAL NOTES. The transfer and
exchange of beneficial interests in the Global Notes shall be effected through
the Depository, in accordance with the Second

                                       16
<Page>

Supplemental Indenture and the Indenture and the procedures of the Depository
therefor. Beneficial interests in the Global Notes may be transferred to Persons
who take delivery thereof in the form of a beneficial interest in the Global
Notes.

               (b)    TRANSFER AND EXCHANGE OF DEFINITIVE NOTES. When Definitive
Notes are presented by a Holder to the Registrar with a request:

                      (x)     to register the transfer of the Definitive Notes;
                              or

                      (y)     to exchange such Definitive Notes for an equal
                              principal amount of Definitive Notes of other
                              authorized denominations, the Registrar shall
                              register the transfer or make the exchange as
                              requested if its requirements for such
                              transactions are met; PROVIDED, HOWEVER, that the
                              Definitive Notes presented or surrendered for
                              register of transfer or exchange shall be duly
                              endorsed or accompanied by a written instruction
                              of transfer in form satisfactory to the Registrar
                              duly executed by such Holder or by his attorney,
                              duly authorized in writing.

               (c)    RESTRICTIONS ON TRANSFER AND EXCHANGE OF GLOBAL NOTES.
Notwithstanding any other provision of the Second Supplemental Indenture or the
Indenture (other than the provisions set forth in subsection (d) of this Section
2.4), the Global Notes may not be transferred as a whole except by the
Depository to a nominee of the Depository, by a nominee of the Depository to the
Depository or to another nominee of the Depository, or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository.

               (d)    AUTHENTICATION OF DEFINITIVE NOTES IN ABSENCE OF
DEPOSITORY. If at any time:

                      (i)     the Depository for the Notes notifies the Company
                              that the Depository is unwilling or unable to
                              continue as Depository for the Global Notes and a
                              successor Depository for the Global Notes is not
                              appointed by the Company within 90 days after
                              delivery of such notice; or

                      (ii)    the Company at its sole discretion, notifies the
                              Trustee in writing that it elects to cause the
                              issuance of Definitive Notes under the Second
                              Supplemental Indenture and the Indenture,

then the Company shall execute, and the Trustee shall, upon receipt of an
authentication order in accordance with Section 2.2 hereof, authenticate and
deliver, Definitive Notes in an aggregate principal amount equal to the
principal amount of the Global Notes in exchange for such Global Notes.

               (e)    CANCELLATION AND/OR ADJUSTMENT OF THE GLOBAL NOTES. At
such time as all beneficial interests in a particular Global Note have been
exchanged for Definitive Notes or a particular Global Note has been redeemed,
repurchased or canceled in whole and not in part, each such Global Note shall be
returned to or retained and canceled by the Trustee in accordance with Section
2.12 of the Indenture. At any time prior to such cancellation, if any beneficial
interest in a Global Note is exchanged for or transferred to a Person who will
take delivery thereof in the form of a beneficial interest in another Global
Note or for Definitive Notes, the principal amount of Notes represented by the
Global Note shall be reduced accordingly and an endorsement shall be made on
such Global Note by the Trustee or by the Depository at the direction of the
Trustee to reflect such reduction; and if the beneficial interest is being
exchanged for or transferred to a Person who will take delivery thereof in the
form of a beneficial interest

                                       17
<Page>

in another Global Note, such other Global Note shall be increased accordingly
and an endorsement will be made on such Global Note by the Trustee or by the
Depository at the direction of the Trustee to reflect such increase.

               (f)    GENERAL PROVISIONS RELATING TO TRANSFERS AND EXCHANGES.

                      (i)     To permit registrations of transfers and
                              exchanges, the Company shall execute and the
                              Trustee shall authenticate Global Notes and
                              Definitive Notes upon receipt of an Authentication
                              Order in accordance with Section 2.2 hereof or at
                              the Registrar's request.

                      (ii)    No service charge shall be made to a Holder of a
                              Global Note or to a Holder of a Definitive Note
                              for any registration of transfer or exchange, but
                              the Company may require payment of a sum
                              sufficient to cover any transfer tax or similar
                              governmental charge payable in connection
                              therewith (other than any such transfer taxes or
                              similar governmental charge payable upon exchange
                              or transfer pursuant to Section 2.4 hereof).

                      (iii)   All Global Notes and Definitive Notes issued upon
                              any registration of transfer or exchange of Global
                              Notes or Definitive Notes shall be the valid
                              obligations of the Company, evidencing the same
                              debt, and entitled to the same benefits under the
                              Second Supplemental Indenture and the Indenture,
                              as the Global Notes or Definitive Notes
                              surrendered upon such registration of transfer or
                              exchange.

                      (iv)    The Company shall not be required to register the
                              transfer of or to exchange a Note between a record
                              date and the next succeeding interest payment
                              date.

                      (iv)    Prior to due presentment for the registration of a
                              transfer of any Note, the Trustee, any Agent, the
                              Company and any Guarantor may deem and treat the
                              Person in whose name any Note is registered as the
                              absolute owner of such Note for all purposes,
                              including receiving payment of principal of and
                              interest on such Notes, and neither the Trustee,
                              any Agent, the Company nor any Guarantor shall be
                              affected by notice to the contrary.

                      (v)     The Trustee shall authenticate Definitive Notes
                              and the Global Notes in accordance with the
                              provisions of Section 2.2 hereof and Section 2.3
                              of the Indenture.

                      (vi)    All certifications, certificates and opinions of
                              counsel required to be submitted to the Registrar
                              pursuant to this Section 2.4 to effect a
                              registration of transfer or exchange may be
                              submitted by facsimile.

Section 2.5.   REDEMPTION.

               With respect to the Notes issued under this Second Supplemental
Indenture, the following Sections supplement Article III of the Indenture:

                                       18
<Page>

               Section  3.7.  OPTIONAL REDEMPTION.

               Prior to July 1, 2008, the Notes shall be subject to redemption
at any time at the option of the Company, in whole or in part, upon not less
than 10 nor more than 60 days' notice, at the Make-Whole Price, plus accrued and
unpaid interest, to but excluding the applicable redemption date. On and after
July 1, 2008, the Notes will be subject to redemption at any time at the option
of the Company, in whole or in part, upon not less than 10 nor more than 60
days' notice, at the redemption price (expressed as percentages of principal
amount) set forth below, plus accrued and unpaid interest to but excluding the
applicable redemption date, if redeemed during the twelve-month period beginning
on July 1 of the years indicated below:

<Table>
<Caption>
               YEAR                                                 PERCENTAGE
               ----                                                 ----------
               <S>                                                    <C>
               2008..............................................     103.313%
               2009..............................................     102.208%
               2010..............................................     101.104%
               2011 and thereafter...............................     100.000%
</Table>

               Notwithstanding the foregoing, at any time prior to July 1, 2006
the Company may on any one or more occasions redeem the Notes at a redemption
price of 106.625% of the principal amount thereof, plus accrued and unpaid
interest, and Liquidated Damages if any, to the redemption date, with the net
cash proceeds of one or more Qualified Equity Offerings; provided that:

               (1)    at least $100.0 million in the aggregate principal amount
                      of the Notes (including any Additional Notes) issued under
                      the Indenture remains outstanding immediately after the
                      occurrence of such redemption (excluding Notes held by the
                      Company and the Company's Subsidiaries); and

               (2)    the redemption must occur within six months of the date of
                      the closing of any such Qualified Equity Offering.

               Section 3.8.   MANDATORY REDEMPTION.

               The Company shall not be required to make mandatory redemption
payments or sinking fund payments with respect to the Notes.

               Section 3.9    ASSET SALE OFFERS.

               In the event that the Company shall commence an Asset Sale Offer
pursuant to Section 4.17 hereof, it shall follow the procedures specified below:

               The Asset Sale Offer shall remain open for 20 Business Days after
the Commencement Date relating to such Asset Sale Offer, except to the extent
required to be extended by applicable law (as so extended, the "OFFER PERIOD").
No later than one Business Day after the termination of the Offer Period (the
"PURCHASE DATE"), the Company shall purchase the principal amount (the "OFFER
AMOUNT") of Notes required to be purchased in such Asset Sale Offer pursuant to
Sections 3.2 and 4.17 hereof or, if less than the Offer Amount has been
tendered, all Notes tendered in response to the Asset Sale Offer.

                                       19
<Page>

               If the Purchase Date is on or after an interest payment record
date and on or before the related interest payment date, any interest accrued to
such Purchase Date shall be paid to the Person in whose name a Note is
registered at the close of business on such record date, and no additional
interest shall be payable to Holders who tender Notes pursuant to the Asset Sale
Offer.

               On the Commencement Date of any Asset Sale Offer, the Company
shall send or cause to be sent, by first class mail, a notice to each of the
Holders, with a copy to the Trustee. Such notice, which shall govern the terms
of the Asset Sale Offer, shall contain all instructions and materials necessary
to enable the Holders to tender Notes pursuant to the Asset Sale Offer and shall
state:

               (1)    that the Asset Sale Offer is being made pursuant to this
                      Section 3.9 and Section 4.17 hereof and the length of time
                      the Asset Sale Offer shall remain open;

               (2)    the Offer Amount, the purchase price and the Purchase
                      Date;

               (3)    that any Note not tendered or accepted for payment shall
                      continue to accrue interest;

               (4)    that, unless the Company defaults in the payment of the
                      purchase price, any Note accepted for payment pursuant to
                      the Asset Sale Offer shall cease to accrue interest after
                      the Purchase Date;

               (5)    that Holders electing to have a Note purchased pursuant to
                      any Asset Sale Offer shall be required to surrender the
                      Note, with the form entitled "Option of Holder to Elect
                      Purchase" on the reverse of the Note completed, to the
                      Company, a depositary, if appointed by the Company, or a
                      Paying Agent at the address specified in the notice prior
                      to the close of business on the Business Day preceding the
                      Purchase Date;

               (6)    that Holders shall be entitled to withdraw their election
                      if the Company, depositary or Paying Agent, as the case
                      may be, receives, not later than the close of business on
                      the Business Day preceding the termination of the Offer
                      Period, a facsimile transmission or letter setting forth
                      the name of the Holder, the principal amount of the Note
                      the Holder delivered for purchase and a statement that
                      such Holder is withdrawing such Holder's election to have
                      the Note purchased;

               (7)    that, if the aggregate principal amount of Notes
                      surrendered by Holders exceeds the Offer Amount, the
                      Trustee shall select the Notes to be purchased on a PRO
                      RATA basis (with such adjustments as may be deemed to be
                      appropriate by the Company so that only Notes in
                      denominations of $1,000, or integral multiples thereof,
                      shall be purchased); and

               (8)    that Holders whose Notes were purchased only in part shall
                      be issued new Notes equal in principal amount to the
                      unpurchased portion of the Notes surrendered.

               On or before 12:00 noon on each Purchase Date, the Company shall
irrevocably deposit with the Trustee or Paying Agent in immediately available
funds the aggregate purchase price with respect to a principal amount of Notes
equal to the Offer Amount, together with accrued interest thereon, to be held
for payment in accordance with the terms of this Section 3.9. On the Purchase
Date, the Company shall, to the extent lawful, (i) accept for payment, on a PRO
RATA basis to the extent necessary, an

                                       20
<Page>

aggregate principal amount equal to the Offer Amount of Notes and other notes
(in accordance with the terms of Section 4.17 of the Indenture) tendered
pursuant to the Asset Sale Offer, or if less than the Offer Amount has been
tendered, all Notes and such other notes or portions thereof tendered, (ii)
deliver or cause the Paying Agent or depositary, as the case may be, to deliver
to the Trustee Notes so accepted and (iii) deliver to the Trustee an Officers'
Certificate stating that such Notes or portions thereof were accepted for
payment by the Company in accordance with the terms of this Section 3.9. The
Company, depositary or Paying Agent, as the case may be, shall promptly (but in
any case not later than three Business Days after the Purchase Date) mail or
deliver to each tendering Holder an amount equal to the purchase price with
respect to the Notes tendered by such Holder and accepted by the Company for
purchase, and the Company shall promptly issue a new Note, and the Trustee shall
authenticate and mail or deliver such new Note, to such Holder, equal in
principal amount to any unpurchased portion of such Holder's Notes surrendered.
Any Note not accepted in the Asset Sale Offer shall be promptly mailed or
delivered by the Company to the Holder thereof. The Company shall publicly
announce in a newspaper of general circulation the results of the Asset Sale
Offer on the Purchase Date.

               The Asset Sale Offer shall be made by the Company in compliance
with all applicable laws, including, without limitation, Regulation 14E of the
Exchange Act and the rules thereunder, to the extent applicable, and all other
applicable federal and state securities laws.

               Each purchase pursuant to this Section 3.9 shall be made pursuant
to the provisions of Sections 3.1 through 3.6 hereof to the extent applicable.

               In the event the amount of Excess Proceeds to be applied to an
Asset Sale Offer would result in the purchase of a principal amount of Notes
which is not evenly divisible by $1,000, the Trustee shall promptly refund to
the Company the portion of such Excess Proceeds that is not necessary to
purchase the immediately lesser principal amount of Notes that is so divisible.

Section 2.6.   COVENANTS.

               With respect to the Notes issued under this Second Supplemental
Indenture, Sections 2.6(a) through 2.6(k) are added to Article IV of the
Indenture.

               (a)    RESTRICTED PAYMENTS.

               Section 4.8. RESTRICTED PAYMENTS. The Company shall not, and
shall not permit any of its Restricted Subsidiaries to, directly or indirectly:

               (1)    declare or pay any dividend or make any distribution on
                      account of the Company's or any of its Restricted
                      Subsidiaries' Equity Interests (other than dividends or
                      distributions payable in Equity Interests (other than
                      Disqualified Stock) of the Company or such Restricted
                      Subsidiary or dividends or distributions payable to the
                      Company or any Restricted Subsidiary);

               (2)    purchase, redeem or otherwise acquire or retire for value
                      any Equity Interests of the Company or any Restricted
                      Subsidiary or other Affiliate of the Company (other than
                      any such Equity Interests owned by the Company or any
                      Restricted Subsidiary);

               (3)    purchase, redeem or otherwise acquire or retire prior to
                      scheduled maturity for value any Indebtedness that is
                      subordinated in right of payment to the Notes; or

                                       21
<Page>

               (4)    make any Investment other than a Permitted Investment (all
                      such payments and other actions set forth in clauses (1)
                      through (4) above being collectively referred to as
                      "RESTRICTED PAYMENTS");

unless, at the time of such Restricted Payment:

                      (i)     no Default or Event of Default shall have occurred
                              and be continuing or would occur as a consequence
                              thereof; and

                      (ii)    the Company would, at the time of such Restricted
                              Payment and after giving pro forma effect thereto,
                              have been permitted to incur at least $1.00 of
                              additional Indebtedness pursuant to the test set
                              forth in the first paragraph of Section 4.9 of the
                              Indenture; and

                      (iii)   such Restricted Payment, together with the
                              aggregate of all other Restricted Payments made by
                              the Company and its Restricted Subsidiaries after
                              the 1996 Indenture Date is less than (x) the
                              cumulative EBITDA of the Company, minus 1.75 times
                              the cumulative Consolidated Interest Expense of
                              the Company, in each case for the period (taken as
                              one accounting period) from June 30, 1996, to the
                              end of the Company's most recently ended fiscal
                              quarter for which internal financial statements
                              are available at the time of such Restricted
                              Payment, plus (y) the aggregate net Equity
                              Proceeds received by the Company from the issuance
                              or sale since the 1996 Indenture Date of Equity
                              Interests of the Company or of debt securities of
                              the Company that have been converted into such
                              Equity Interests (other than Equity Interests or
                              convertible debt securities sold to a Restricted
                              Subsidiary of the Company and other than
                              Disqualified Stock or debt securities that have
                              been converted into Disqualified Stock), plus (z)
                              $2.0 million.

               The foregoing provisions will not prohibit:

               (1)    the payment of any dividend within 60 days after the date
                      of declaration thereof, if at said date of declaration
                      such payment would have complied with the provisions of
                      the Indenture;

               (2)    the redemption, repurchase, retirement or other
                      acquisition or retirement for value of any Equity
                      Interests of the Company in exchange for, or with the net
                      cash proceeds of, the substantially concurrent sale (other
                      than to a Restricted Subsidiary of the Company) of other
                      Equity Interests of the Company (other than any
                      Disqualified Stock);

               (3)    the defeasance, redemption, repurchase, retirement or
                      other acquisition or retirement for value of Indebtedness
                      that is subordinated in right of payment to the Notes in
                      exchange for, or with the net cash proceeds of, a
                      substantially concurrent issuance and sale (other than to
                      a Restricted Subsidiary of the Company) of Equity
                      Interests of the Company (other than Disqualified Stock);

               (4)    the defeasance, redemption, repurchase, retirement or
                      other acquisition or retirement for value of Indebtedness
                      that is subordinated in right of payment to

                                       22
<Page>

                      the Notes in exchange for, or with the net cash proceeds
                      of, a substantially concurrent issue and sale (other than
                      to the Company or any of its Restricted Subsidiaries) of
                      Refinancing Indebtedness;

               (5)    the repurchase of any Indebtedness subordinated in right
                      of payment to the Notes at a purchase price not greater
                      than 101% of the principal amount of such Indebtedness in
                      the event of a Change of Control in accordance with
                      provisions similar to the covenant set forth in Section
                      4.18 of the Indenture, provided that prior to or
                      contemporaneously with such repurchase the Company has
                      made the Change of Control Offer as provided in such
                      covenant with respect to the Notes and has repurchased all
                      Notes validly tendered for payment in connection with such
                      Change of Control Offer; and

               (6)    additional payments to current or former employees or
                      directors of the Company for repurchases of stock, stock
                      options or other equity interests, provided that the
                      aggregate amount of all such payments under this clause
                      (6) does not exceed $0.5 million in any year and $2.0
                      million in the aggregate.

               The Restricted Payments described in clauses (2), (3), (5) and
(6) of the immediately preceding paragraph shall be Restricted Payments that
shall be permitted to be taken in accordance with such paragraph but shall
reduce the amount that would otherwise be available for Restricted Payments
under clause (iii) of the first paragraph of this Section, and the Restricted
Payments described in clauses (1) and (4) of the immediately preceding paragraph
shall be Restricted Payments that shall be permitted to be taken in accordance
with such paragraph and shall not reduce the amount that would otherwise be
available for Restricted Payments under clause (iii) of the first paragraph of
this Section.

               If an Investment results in the making of a Restricted Payment,
the aggregate amount of all Restricted Payments deemed to have been made as
calculated under the foregoing provision shall be reduced by the amount of any
net reduction in such Investment (resulting from the payment of interest or
dividends, loan repayment, transfer of assets or otherwise) to the extent such
net reduction is not included in the Company's EBITDA; PROVIDED, HOWEVER, that
the total amount by which the aggregate amount of all Restricted Payments may be
reduced may not exceed the lesser of (a) the cash proceeds received by the
Company and its Restricted Subsidiaries in connection with such net reduction
and (b) the initial amount of such Investment.

               If the aggregate amount of all Restricted Payments calculated
under the foregoing provision includes an Investment in an Unrestricted
Subsidiary or other Person that thereafter becomes a Restricted Subsidiary, such
Investment will no longer be counted as a Restricted Payment for purposes of
calculating the aggregate amount of Restricted Payments. For the purpose of
making any calculations under the Indenture:

               (1)    an Investment shall include the fair market value of the
                      net assets of any Restricted Subsidiary at the time that
                      such Restricted Subsidiary is designated an Unrestricted
                      Subsidiary and shall exclude the fair market value of the
                      net assets of any Unrestricted Subsidiary that is
                      designated as a Restricted Subsidiary;

               (2)    any property transferred to or from an Unrestricted
                      Subsidiary shall be valued at fair market value at the
                      time of such transfer, provided that, in each case, the
                      fair market value of an asset or property is as determined
                      by the Board of Directors in good faith; and

                                       23
<Page>

               (3)    subject to the foregoing, the amount of any Restricted
                      Payment, if other than cash, shall be determined by the
                      Board of Directors, whose good faith determination shall
                      be conclusive.

               The Board of Directors may designate a Restricted Subsidiary to
be an Unrestricted Subsidiary in compliance with the Section 4.15 of the
Indenture. Upon such designation, all outstanding Investments by the Company and
its Restricted Subsidiaries (except to the extent repaid in cash) in the
Subsidiary so designated will be deemed to be Restricted Payments made at the
time of such designation and will reduce the amount available for Restricted
Payments under the first paragraph of this covenant. Such designation will only
be permitted if such Restricted Payment would be permitted at such time and if
such Restricted Subsidiary otherwise meets the definition of an Unrestricted
Subsidiary.

               (b) INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED STOCK.

               Section 4.9. INCURRENCE OF INDEBTEDNESS AND ISSUANCE OF PREFERRED
STOCK. The Company shall not, and shall not permit any of its Restricted
Subsidiaries to, directly or indirectly, create, incur, issue, assume, guaranty
or otherwise become directly or indirectly liable with respect to (collectively,
"INCUR") any Indebtedness (including Acquired Debt) and the Company shall not
permit any of its Restricted Subsidiaries to issue any shares of preferred
stock; provided, however, that the Company may incur Indebtedness and may permit
a Restricted Subsidiary to incur Indebtedness if at the time of such incurrence
and after giving effect thereto the Leverage Ratio would be less than 6.5 to
1.0.

               The foregoing limitations shall not apply to:

               (1)    the incurrence by the Company or any Restricted Subsidiary
                      of Senior Bank Debt in an aggregate amount not to exceed
                      $100.0 million at any one time outstanding;

               (2)    the issuance by the Restricted Subsidiaries of Subsidiary
                      Guarantees;

               (3)    the incurrence by the Company and its Restricted
                      Subsidiaries of the Existing Indebtedness;

               (4)    the issuance by the Company of the Notes;

               (5)    the incurrence by the Company and its Restricted
                      Subsidiaries of Capital Lease Obligations and/or
                      additional Indebtedness constituting purchase money
                      obligations up to an aggregate of $5.0 million at any one
                      time outstanding, provided that the Liens securing such
                      Indebtedness constitute Permitted Liens;

               (6)    the incurrence of Indebtedness between (i) the Company and
                      its Restricted Subsidiaries and (ii) the Restricted
                      Subsidiaries;

               (7)    Hedging Obligations that are incurred for the purpose of
                      fixing or hedging interest rate risk with respect to any
                      floating rate Indebtedness that is permitted by the terms
                      of the Indenture to be outstanding;

               (8)    the incurrence by the Company and its Restricted
                      Subsidiaries of Indebtedness arising out of letters of
                      credit, performance bonds, surety bonds and bankers'
                      acceptances incurred in the ordinary course of business up
                      to an aggregate of $5.0 million at any one time
                      outstanding;

                                       24
<Page>

               (9)    the incurrence by the Company and its Restricted
                      Subsidiaries of Indebtedness consisting of guarantees,
                      indemnities or obligations in respect of purchase price
                      adjustments in connection with the acquisition or
                      disposition of assets, including, without limitation,
                      shares of Capital Stock; and

               (10)   the incurrence by the Company and its Restricted
                      Subsidiaries of Refinancing Indebtedness issued in
                      exchange for, or the proceeds of which are used to repay,
                      redeem, defease, extend, refinance, renew, replace or
                      refund, Indebtedness referred to in clauses (2) through
                      (5) above, and this clause (10) or that was otherwise
                      permitted to be incurred pursuant to the test set forth in
                      the first paragraph of this Section 4.9.

               (c)    LIENS.

               Section 4.10. LIENS. Neither the Company nor any of its
Restricted Subsidiaries may directly or indirectly create, incur, assume or
suffer to exist any Lien (other than a Permitted Lien) upon any property or
assets now owned or hereafter acquired, or any income, profits or proceeds
therefrom, or assign or otherwise convey any right to receive income therefrom,
unless (a) in the case of any Lien securing any Indebtedness that is subordinate
to the Notes, the Notes are secured by a Lien on such property, assets or
proceeds that is senior in priority to such Lien and (b) in the case of any
other Lien, the Notes are equally and ratably secured with the obligation or
liability secured by such Lien.

               (d) DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING RESTRICTED
SUBSIDIARIES.

          Section 4.11. DIVIDEND AND OTHER PAYMENT RESTRICTIONS AFFECTING
RESTRICTED SUBSIDIARIES. The Company shall not, and shall not permit any of its
Restricted Subsidiaries to, directly or indirectly, create or otherwise cause or
suffer to exist or become effective any encumbrance or restriction on the
ability of any Restricted Subsidiary to:

               (1)    (i) pay dividends or make any other distributions to the
                      Company or any of its Restricted Subsidiaries (A) on its
                      Capital Stock or (B) with respect to any other interest or
                      participation in, or measured by, its profits, or (ii) pay
                      any Indebtedness owed to the Company or any of its
                      Restricted Subsidiaries;

               (2)    make loans or advances to the Company or any of its
                      Restricted Subsidiaries; or

               (3)    transfer any of its properties or assets to the Company or
                      any of its Restricted Subsidiaries.

               However, the preceding restrictions will not apply to
encumbrances or restrictions existing under or by reason of:

               (1)    Existing Indebtedness;

               (2)    the Credit Agreement as in effect as of the date of the
                      Indenture, and any amendments, modifications,
                      restatements, renewals, increases, supplements,
                      refundings, replacements or refinancing thereof, provided
                      that such amendments, modifications, restatements,
                      renewals, increases, supplements, refundings, replacements
                      or refinancings are no more restrictive in the aggregate
                      with respect

                                       25
<Page>

                      to such dividend and other payment restrictions than those
                      contained in the Credit Agreement as in effect on the date
                      of the Indenture;

               (3)    the Indenture and the Notes;

               (4)    applicable law;

               (5)    any instrument governing Indebtedness or Capital Stock of
                      a Person acquired by the Company or any of its Restricted
                      Subsidiaries as in effect at the time of such acquisition
                      (except to the extent such Indebtedness was incurred in
                      connection with or in contemplation of such acquisition),
                      which encumbrance or restriction is not applicable to any
                      Person, or the properties or assets of any Person, other
                      than the Person, or the property or assets of the Person,
                      so acquired, provided that the EBITDA of such Person is
                      not taken into account in determining whether such
                      acquisition was permitted by the terms of the Indenture;

               (6)    customary non-assignment provisions in leases entered into
                      in the ordinary course of business and consistent with
                      past practices;

               (7)    restrictions on the transfer of property subject to
                      purchase money obligations or Capital Lease Obligations
                      otherwise permitted by clause (5) of Section 4.9 of the
                      Indenture;

               (8)    permitted Refinancing Indebtedness, provided that the
                      restrictions contained in the agreements governing such
                      Refinancing Indebtedness are no more restrictive in the
                      aggregate than those contained in the agreements governing
                      the Indebtedness being refinanced; or

               (9)    any agreement or instrument governing Indebtedness of an
                      Excluded Restricted Subsidiary provided that (i) at the
                      time such agreement or instrument is entered into, such
                      Excluded Restricted Subsidiary and its Restricted
                      Subsidiaries have a Leverage Ratio of less than 6.5 to 1.0
                      and (ii) neither such Excluded Restricted Subsidiary nor
                      any of its Restricted Subsidiaries shall, directly or
                      indirectly, incur any Indebtedness (including Acquired
                      Debt) unless at the time of such incurrence and after
                      giving effect thereto, the Leverage Ratio for such
                      Excluded Restricted Subsidiary and its Restricted
                      Subsidiaries would be less than 6.5 to 1.0. For purposes
                      of determining the Leverage Ratio under this clause (9)
                      only, all references to the "Company" and its "Restricted
                      Subsidiaries" or similar references in the definition of
                      "Leverage Ratio" and other defined terms necessary to
                      determine the Leverage Ratio shall be deemed to refer to
                      such Excluded Restricted Subsidiary and its Restricted
                      Subsidiaries, respectively.

               (e) TRANSACTIONS WITH AFFILIATES.

               Section 4.12. TRANSACTIONS WITH AFFILIATES. The Company shall
not, and shall not permit any of its Restricted Subsidiaries to, sell, lease,
transfer or otherwise dispose of any of its properties or assets to, or purchase
any property or assets from, or enter into any contract, agreement,
understanding, loan, advance or guarantee with, or for the benefit of, any
Affiliate (each of the foregoing, an "AFFILIATE TRANSACTION"), unless:

                                       26
<Page>

               (a)    such Affiliate Transaction is on terms that are no less
                      favorable to the Company or the relevant Restricted
                      Subsidiary than those that would have been obtained in a
                      comparable transaction by the Company or such Restricted
                      Subsidiary with a non-Affiliated Person; and

               (b)    the Company delivers to the Trustee:

                      (i)     with respect to any Affiliate Transaction
                              involving aggregate payments in excess of $5.0
                              million, a resolution of the Board of Directors
                              set forth in an Officers' Certificate certifying
                              that such Affiliate Transaction complies with
                              clause (a) above and such Affiliate Transaction is
                              approved by a majority of the disinterested
                              members of the Board of Directors; and

                      (ii)    with respect to any Affiliate Transaction
                              involving aggregate payments in excess of $10.0
                              million, an opinion as to the fairness to the
                              Company or such Restricted Subsidiary from a
                              financial point of view issued by an investment
                              banking firm of national standing.

               The following items shall not be deemed Affiliate Transactions
and therefore, will not be subject to the provisions of the prior paragraph:

               (1)    any employment agreement entered into by the Company or
                      any of its Restricted Subsidiaries in the ordinary course
                      of business and consistent with the past practice of the
                      Company or such Restricted Subsidiary;

               (2)    transactions between or among the Company and/or its
                      Restricted Subsidiaries;

               (3)    transactions permitted by the provisions of Section 4.8 of
                      the Indenture; and

               (4)    the grant of stock, stock options or other equity
                      interests to employees and directors of the Company and
                      any Restricted Subsidiary in accordance with duly adopted
                      Company stock grant, stock option and similar plans.

               The provisions set forth in clause (b) above shall not apply to
sales of inventory by the Company or any Restricted Subsidiary to any Affiliate
in the ordinary course of business. The provisions of clause (b) (ii) above
shall not apply to loans or advances to the Company or any Restricted Subsidiary
from, or equity investments in the Company or any Restricted Subsidiary by, any
Affiliate to the extent permitted by the provisions of Section 4.9 of the
Indenture.

               (f) CERTAIN SENIOR SUBORDINATED DEBT.

               Section 4.13. CERTAIN SENIOR SUBORDINATED DEBT. The Company shall
not incur any Indebtedness that is subordinated or junior in right of payment to
any Senior Debt of the Company and senior in any respect in right of payment to
the Notes. The Company shall not permit any Restricted Subsidiary to incur any
Indebtedness that is subordinated or junior in right of payment to its Senior
Debt and senior in any respect in right of payment to its Subsidiary Guarantee.

               (g) ADDITIONAL SUBSIDIARY GUARANTEES.

                                       27
<Page>

               Section 4.14. ADDITIONAL SUBSIDIARY GUARANTEES. If any entity
(other than an Excluded Restricted Subsidiary) shall become a Restricted
Subsidiary after the date of the Second Supplemental Indenture, then such
Restricted Subsidiary shall execute a supplemental indenture in the form of
Exhibit B attached hereto, pursuant to which it shall provide a Subsidiary
Guarantee and deliver an Opinion of Counsel with respect thereto, in accordance
with the terms of the Indenture.

               No Restricted Subsidiary (including any Excluded Restricted
Subsidiary) shall consolidate with or merge with or into (whether or not such
Restricted Subsidiary is the surviving Person), another Person (other than the
Company) whether or not affiliated with such Restricted Subsidiary unless:

               (1)    subject to the provisions of the following paragraph, the
                      Person formed by or surviving any such consolidation or
                      merger (if other than such Restricted Subsidiary) assumes
                      all the obligations of such Restricted Subsidiary under
                      its Subsidiary Guarantee (except in the case of an
                      Excluded Restricted Subsidiary) pursuant to a supplemental
                      indenture in form and substance reasonably satisfactory to
                      the Trustee;

               (2)    immediately after giving effect to such transaction, no
                      Default or Event of Default exists; and

               (3)    such Restricted Subsidiary, or any Person formed by or
                      surviving any such consolidation or merger, would be
                      permitted to incur, immediately after giving effect to
                      such transaction, at least $1.00 of additional
                      Indebtedness pursuant to the test set forth in the first
                      paragraph of Section 4.9 of the Indenture.

In the event of:

               (1)    a sale or other disposition of all of the assets of any
                      Restricted Subsidiary, by way of merger, consolidation or
                      otherwise;

               (2)    a sale or other disposition of all of the capital stock of
                      any Restricted Subsidiary; or

               (3)    the designation of a Restricted Subsidiary as an
                      Unrestricted Subsidiary in accordance with the terms of
                      Section 4.15 of the Indenture,

then such Restricted Subsidiary (in the event of a sale or other disposition, by
way of such a merger, consolidation or otherwise, of all of the capital stock of
such Restricted Subsidiary or in the event of the designation of such Restricted
Subsidiary as an Unrestricted Subsidiary) or the Person acquiring the property
(in the event of a sale or other disposition of all of the assets of such
Restricted Subsidiary) will be released and relieved of any obligations under
its Subsidiary Guarantee, provided that the Net Proceeds of such sale or other
disposition are applied in accordance with the applicable provisions of Section
4.17 of the Indenture.

               (h) DESIGNATION OF UNRESTRICTED SUBSIDIARIES.

               Section 4.15. DESIGNATION OF UNRESTRICTED SUBSIDIARIES. The Board
of Directors may designate any Subsidiary (including any Restricted Subsidiary
or any newly acquired or newly formed Subsidiary) to be an Unrestricted
Subsidiary so long as:

                                       28
<Page>

               (1)    neither the Company nor any Restricted Subsidiary is
                      directly or indirectly liable for any Indebtedness of such
                      Subsidiary;

               (2)    no default with respect to any Indebtedness of such
                      Subsidiary would permit (upon notice, lapse of time or
                      otherwise) any holder of any other Indebtedness of the
                      Company or any Restricted Subsidiary to declare a default
                      on such other Indebtedness or cause the payment thereof to
                      be accelerated or payable prior to its stated maturity;

               (3)    any Investment in such Subsidiary deemed to be made as a
                      result of designating such Subsidiary an Unrestricted
                      Subsidiary will not violate the provisions of Section 4.8
                      of the Indenture;

               (4)    neither the Company nor any Restricted Subsidiary has a
                      contract, agreement, arrangement, understanding or
                      obligation of any kind, whether written or oral, with such
                      Subsidiary other than (A) those that might be obtained at
                      the time from Persons who are not Affiliates of the
                      Company or (B) administrative, tax sharing and other
                      ordinary course contracts, agreements, arrangements and
                      understandings or obligations entered into in the ordinary
                      course of business; and

               (5)    neither the Company nor any Restricted Subsidiary has any
                      obligation to subscribe for additional shares of Capital
                      Stock or other Equity Interests in such Subsidiary, or to
                      maintain or preserve such Subsidiary's financial condition
                      or to cause such Subsidiary to achieve certain levels of
                      operating results other than as permitted under Section
                      4.8 of the Indenture.

               Notwithstanding the foregoing, the Company may not designate as
an Unrestricted Subsidiary any Subsidiary which, on the 1999 Indenture Date, was
a Significant Subsidiary, and may not sell, transfer or otherwise dispose of any
properties or assets of any such Significant Subsidiary to an Unrestricted
Subsidiary, other than in the ordinary course of business, in each case other
than Iron Mountain Global, Inc. and its Subsidiaries (including without
limitation Iron Mountain Europe Limited and its Subsidiaries).

               The Board of Directors may designate any Unrestricted Subsidiary
as a Restricted Subsidiary; provided that such designation will be deemed to be
an incurrence of Indebtedness by a Restricted Subsidiary of any outstanding
Indebtedness of such Unrestricted Subsidiary and such designation will only be
permitted if:

               (1)    such Indebtedness is permitted under Section 4.9 of the
                      Indenture; and

               (2)    no Default or Event of Default would occur as a result of
                      such designation.

               (i) LIMITATION ON SALE AND LEASEBACK TRANSACTIONS.


               Section 4.16. LIMITATION ON SALE AND LEASEBACK TRANSACTIONS. The
Company will not, and will not permit any Restricted Subsidiary to, enter into
any Sale and Leaseback Transaction unless:

               (1)    the consideration received in such Sale and Leaseback
                      Transaction is at least equal to the fair market value of
                      the property sold, as determined by a resolution of the
                      Board of Directors; and

                                       29
<Page>

               (2)    the Company or such Restricted Subsidiary could incur the
                      Attributable Indebtedness in respect of such Sale and
                      Leaseback Transaction in compliance with Section 4.9 of
                      the Indenture.

               (j) ASSET SALES.

               Section 4.17. ASSET SALES. The Company shall not, and shall not
permit any of its Restricted Subsidiaries to:

               (1)    sell, lease, convey or otherwise dispose of any assets
                      (including by way of a Sale and Leaseback Transaction, but
                      excluding a Qualifying Sale and Leaseback Transaction)
                      other than sales of inventory in the ordinary course of
                      business (provided that the sale, lease, conveyance or
                      other disposition of all or substantially all of the
                      assets of the Company will be governed by the provisions
                      of Section 4.18 of the Indenture and/or the provisions of
                      Section 5.1 of the Indenture and not by the provisions of
                      this Section 4.17); or

               (2)    issue or sell Equity Interests of any of its Restricted
                      Subsidiaries

that in the case of either clause (1) or (2) above, whether in a single
transaction or a series of related transactions:

               (i)    have a fair market value in excess of $2.0 million; or

               (ii)   result in Net Proceeds in excess of $2.0 million (each of
                      the foregoing, an "ASSET SALE"), unless (x) the Company
                      (or the Restricted Subsidiary, as the case may be)
                      receives consideration at the time of such Asset Sale at
                      least equal to the fair market value (evidenced by an
                      Officers' Certificate delivered to the Trustee, and for
                      Asset Sales having a fair market value or resulting in Net
                      Proceeds in excess of $10.0 million, evidenced by a
                      resolution of the Board of Directors set forth in an
                      Officers' Certificate delivered to the Trustee) of the
                      assets sold or otherwise disposed of and (y) at least 75%
                      of the consideration therefor received by the Company or
                      such Restricted Subsidiary is in the form of cash or
                      like-kind assets (in each case as determined in good faith
                      by the Company, evidenced by a resolution of the Board of
                      Directors and certified by an Officers' Certificate
                      delivered to the Trustee);

provided, however, that the amount of:

               (A)    any liabilities (as shown on the Company's or such
                      Restricted Subsidiary's most recent balance sheet or in
                      the notes thereto) of the Company or such Restricted
                      Subsidiary (other than liabilities that are by their terms
                      subordinated to the Notes or any Subsidiary Guarantee)
                      that are assumed by the transferee of any such assets; and

               (B)    any notes or other obligations received by the Company or
                      such Restricted Subsidiary from such transferee that are
                      immediately converted by the Company or such Restricted
                      Subsidiary into cash (to the extent of the cash received)
                      or Cash Equivalents,

                                       30
<Page>

shall be deemed to be cash for purposes of this provision; and provided,
further, that the 75% limitation referred to in the foregoing clause (ii) (y)
shall not apply to any Asset Sale in which the cash portion of the consideration
received therefrom is equal to or greater than what the after-tax proceeds would
have been had such Asset Sale complied with the aforementioned 75% limitation.

               A transfer of assets or issuance of Equity Interests by the
Company to a Wholly Owned Restricted Subsidiary or by a Wholly Owned Restricted
Subsidiary to the Company or to another Wholly Owned Restricted Subsidiary will
not be deemed to be an Asset Sale.

               Within 360 days of any Asset Sale, the Company may, at its
option, apply an amount equal to the Net Proceeds from such Asset Sale either:

               (1)    to permanently reduce Senior Debt; or

               (2)    to an investment in a Restricted Subsidiary or in another
                      business or capital expenditure or other
                      long-term/tangible assets, in each case, in the same line
                      of business as the Company or any of its Restricted
                      Subsidiaries was engaged in on the date of the Second
                      Supplemental Indenture or in businesses similar or
                      reasonably related thereto.

               Pending the final application of any such Net Proceeds, the
Company may temporarily reduce Senior Bank Debt or otherwise invest such Net
Proceeds in any manner that is not prohibited by the Indenture. Any Net Proceeds
from such Asset Sale that are not applied or invested as provided in the first
sentence of this paragraph will be deemed to constitute "EXCESS PROCEEDS." When
the aggregate amount of Excess Proceeds exceeds $10.0 million, the Company shall
make an offer to all Holders of the Notes, all holders of the 8 1/4% Notes, the
8 1/8% Notes, the 8 5/8% Notes and the 7 3/4% Notes and the holders of any
future Indebtedness ranking PARI PASSU with the Notes, which Indebtedness
contains similar provisions requiring the Company to repurchase such
Indebtedness (an "ASSET SALE OFFER"), to purchase the maximum principal amount
of Notes and such other Indebtedness that may be purchased out of the Excess
Proceeds, at an offer price in cash in an amount equal to 100% of the principal
amount thereof plus accrued and unpaid interest, if any, to the date of
purchase, in accordance with the procedures set forth in the Indenture. To the
extent that the aggregate amount of Notes and other PARI PASSU Indebtedness
(including the 8 1/4% Notes, the 8 1/8% Notes, the 8 5/8% Notes and the 7 3/4%
Notes) tendered pursuant to an Asset Sale Offer is less than the Excess
Proceeds, the Company may use any remaining Excess Proceeds for general
corporate purposes. If the aggregate principal amount of Notes and such other
Indebtedness surrendered by Holders thereof exceeds the amount of Excess
Proceeds, the Trustee shall select the Notes and such other Indebtedness to be
purchased on a pro rata basis. Upon completion of such offer to purchase, the
amount of Excess Proceeds shall be reset at zero.

               The Company shall comply with the requirements of Rule 14e-1
under the Exchange Act and any other securities laws and regulations thereunder
to the extent those laws and regulations are applicable in connection with each
repurchase of Notes pursuant to an Asset Sale Offer. To the extent that the
provisions of any securities laws or regulations conflict with the provisions of
this Section 4.17, the Company shall comply with the applicable securities laws
and regulations and shall not be deemed to have breached its obligations under
the Asset Sale provisions of the Indenture by virtue of such conflict.

               An Asset Sale Offer shall be made pursuant to the provisions of
Section 3.9 hereof. No later than the date which is five Business Days after the
date on which the aggregate amount of Excess Proceeds exceeds $10.0 million, the
Company shall notify the Trustee of such Asset Sale Offer and provide the
Trustee with an Officers' Certificate setting forth the calculations used in
determining the

                                       31
<Page>

amount of Net Proceeds to be applied to the purchase of Notes. The Company shall
commence or cause to be commenced the Asset Sale Offer on a date no later than
15 Business Days after such notice (the "COMMENCEMENT DATE").

               (k) CHANGE OF CONTROL OFFER.

               Section 4.18. CHANGE OF CONTROL OFFER.

               (a) Upon the occurrence of a Change of Control, each Holder of
Notes shall have the right to require the Company to repurchase all or any part
(equal to $1,000 or an integral multiple thereof) of such Holder's Notes
pursuant to the offer described below (the "CHANGE OF CONTROL OFFER") at an
offer price in cash equal to 101% of the aggregate principal amount thereof plus
accrued and unpaid interest to but excluding the date of repurchase (the "CHANGE
OF CONTROL PAYMENT").

               Within 30 calendar days following any Change of Control, the
Company shall mail a notice to each Holder, with a copy to the Trustee, stating:

               (1)    that the Change of Control Offer is being made pursuant to
                      this Section 4.18 and that all Notes tendered shall be
                      accepted for payment;

               (2)    the purchase price and the purchase date, which shall be
                      no earlier than 30 calendar days nor later than 60
                      calendar days from the date such notice is mailed (the
                      "CHANGE OF CONTROL PAYMENT DATE");

               (3)    that any Note not tendered shall continue to accrue
                      interest;

               (4)    that, unless the Company defaults in the payment of the
                      Change of Control Payment, all Notes accepted for payment
                      pursuant to the Change of Control Offer shall cease to
                      accrue interest on and after the Change of Control Payment
                      Date;

               (5)    that Holders electing to have any Notes purchased pursuant
                      to a Change of Control Offer shall be required to
                      surrender the Notes, with the form entitled "Option of
                      Holder to Elect Purchase" on the reverse of the Notes
                      completed, to the Paying Agent at the address specified in
                      such notice prior to the close of business on the fifth
                      Business Day preceding the Change of Control Payment Date;

               (6)    that Holders will be entitled to withdraw their election
                      if the Paying Agent receives, not later than the close of
                      business on the second Business Day preceding the Change
                      of Control Payment Date, facsimile transmission or letter
                      setting forth the name of the Holder, the principal amount
                      of Notes delivered for purchase, and a statement that such
                      Holder is withdrawing its election to have such Notes
                      purchased; and

               (7)    that Holders whose Notes are being purchased only in part
                      will be issued new Notes equal in principal amount to the
                      unpurchased portion of the Notes surrendered, which
                      unpurchased portion must be equal to $1,000 in principal
                      amount or an integral multiple thereof.

               The Company shall comply with the requirements of Rule 14e-1
under the Exchange Act and any other securities laws and regulations thereunder,
to the extent such laws and regulations are

                                       32
<Page>

applicable to the repurchase of the Notes in connection with a Change of
Control. To the extent that the provisions of any securities laws or regulations
conflict with this Section 4.18, the Company shall comply with the applicable
securities laws and regulations and shall not be deemed to have breached its
obligations under the Change of Control provisions of the Indenture or the
Second Supplemental Indenture by virtue of such conflict.

               (b)    On the Change of Control Payment Date, the Company shall,
to the extent lawful:

               (1)    accept for payment Notes or portions thereof tendered
                      pursuant to the Change of Control Offer;

               (2)    deposit with the Paying Agent an amount equal to the
                      Change of Control Payment in respect of all Notes or
                      portions thereof so tendered; and

               (3)    deliver or cause to be delivered to the Trustee the Notes
                      so accepted together with an Officers' Certificate stating
                      the Notes or portions thereof tendered to the Company.

               The Paying Agent shall promptly mail to each Holder of Notes so
accepted the Change of Control Payment for such Notes, and the Trustee shall
promptly authenticate and mail to each Holder a new Note equal in principal
amount to any unpurchased portion of the Notes surrendered, if any; provided
that each such new Note shall be in a principal amount of $1,000 or an integral
multiple thereof. Prior to complying with the provisions of this Section 4.18,
but in any event within 90 calendar days following a Change of Control, the
Company shall either repay all outstanding Senior Debt or obtain the requisite
consents, if any, under all agreements governing outstanding Senior Debt to
permit the repurchase of Notes required by this Section 4.18. The Company shall
publicly announce in The Wall Street Journal, or if no longer published, a
national newspaper of general circulation, the results of the Change of Control
Offer on or as soon as practicable after the Change of Control Payment Date.

               The Company shall not be required to make a Change of Control
Offer upon a Change of Control if a third party makes the Change of Control
Offer in the manner, at the times and otherwise in compliance with the
requirements set forth in this Section 4.18 applicable to a Change of Control
Offer made by the Company and purchases all Notes properly tendered and not
withdrawn under the Change of Control Offer.

Section 2.7.   SUBSIDIARY GUARANTEES.

               With respect to the Notes issued under this Supplemental
Indenture, Article XII of the Indenture shall apply, and the Notes shall
constitute a Series to be guaranteed by the Guarantors pursuant to Article XII
of the Indenture.

Section 2.8.   LEGAL DEFEASANCE AND COVENANT DEFEASANCE.

               With respect to the Notes issued under this Supplemental
Indenture, Article VIII of the Indenture shall apply, and the Company shall have
the option to effect Legal Defeasance or Covenant Defeasance pursuant to Article
VIII of the Indenture. In connection with any Covenant Defeasance, the Company
shall be released from its obligations under the covenants specified in Section
5.1 of the Indenture and Section 2.6 of this Second Supplemental Indenture.

                                       33
<Page>

Section 2.9.   SUBORDINATION

               With respect to the Notes issued under this Supplemental
Indenture, Article XIII of the Indenture shall apply, and the Notes shall be
subject to subordination pursuant to Article XIII of the Indenture.

                                   ARTICLE 3.

                                  MISCELLANEOUS

Section 3.1.   EFFECT OF HEADINGS.

               The Article and Section headings herein are for convenience only
and shall not affect the construction hereof.

Section 3.2.   SUCCESSORS AND ASSIGNS.

               All covenants and agreements in this Second Supplemental
Indenture by the Company shall bind its successors and assigns, whether so
expressed or not.

Section 3.3.   SEPARABILITY CLAUSE.

               In case any provision in this Second Supplemental Indenture or in
the Notes shall be invalid, illegal or unenforceable, the validity, legality and
enforceability of the remaining provisions shall not in any way be affected or
impaired thereby.

Section 3.4.   GOVERNING LAW.

               This Second Supplemental Indenture and the Notes created hereby
shall be governed by and construed in accordance with the laws of the State of
New York without giving effect to any conflicts of law provisions (other than
Section 5-1401 of the New York General Obligations Law) that might cause this
Second Supplemental Indenture and the Notes to be governed by or construed or
enforced in accordance with the laws of any other jurisdiction.

Section 3.5.   SECOND SUPPLEMENT TO SUPERSEDE INDENTURE.

               The Indenture, as supplemented by the Second Supplemental
Indenture, remains in full force and effect as of the date hereof.
Notwithstanding the foregoing, to the extent that any provision of the Indenture
shall conflict with any provision of this Second Supplemental Indenture, the
terms of this Second Supplemental Indenture shall be deemed controlling and the
conflicting provision of the Indenture shall be null and void to the extent of
such conflict.


           [THE REST OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK.]

                                       34
<Page>

               IN WITNESS WHEREOF, the parties have caused this Second
Supplemental Indenture to be duly executed, and attested, all as of the date and
year first written above.

                                         Iron Mountain Incorporated


                                         By:    /s/ C. Richard Reese
                                         Name:  C. Richard Reese
                                         Title: President


                                         COMAC, Inc., Data Security and
                                         Storage, Inc., DSI Technology
                                         Escrow Services, Inc., Iron
                                         Mountain Global, Inc., Iron
                                         Mountain Information Management,
                                         Inc., Mountain Real Estate Assets,
                                         Inc., Mountain Reserve I, Inc. and
                                         Mountain Reserve II, Inc.

                                         By:   /s/ C. Richard Reese
                                         Name: C. Richard Reese
                                         Title: Sole Director


                                         Iron Mountain Global, LLC

                                         By: Iron Mountain Global, Inc.,
                                                    its sole member

                                         By:   /s/ C. Richard Reese
                                         Name: C. Richard Reese
                                         Title: Sole Director


                                         Iron Mountain Business Trust #1

                                         By:   /s/ C. Richard Reese
                                         Name: C. Richard Reese
                                         Title: Trustee

                                         By:   /s/ John F. Kenny, Jr.
                                         Name: John F. Kenny, Jr.
                                         Title: Trustee

                                         By:   /s/ Garry B. Watzke
                                         Name: Garry B. Watzke
                                         Title: Trustee


                 [Second Supplemental Indenture Signature Page]

<Page>

                                         THE BANK OF NEW YORK, as Trustee


                                         By:   /s/ Kisha A. Holder
                                         Name: Kisha A. Holder
                                         Title:  Assistant Vice President


                 [Second Supplemental Indenture Signature Page]

<Page>

                                                                       Exhibit A

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


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

                                 [Face of Note]
                    6-5/8% Senior Subordinated Notes due 2016

CUSIP No.  462846 AC 0                                              $150,000,000


                           IRON MOUNTAIN INCORPORATED

promises to pay to CEDE & Co. or registered assigns, the principal sum of One
Hundred Fifty Million Dollars on January 1, 2016.

               Interest Payment Dates: January 1 and July 1

               Record Dates: December 15 and June 15

               Dated: June 20, 2003


                                         IRON MOUNTAIN INCORPORATED


                                         By:
                                               ---------------------------
                                         Name:
                                         Title:


                                         By:
                                               ---------------------------
                                         Name:
                                         Title


                                     (SEAL)

This is one of the Notes
referred to in the within-
mentioned Indenture:

THE BANK OF NEW YORK,
as Trustee


By:
     ------------------------------------
             Authorized Signature

<Page>

                    6-5/8% Senior Subordinated Notes due 2016

               This Security is a Global Security within the meaning of the
Indenture hereinafter referred to and is registered in the name of the
Depository or a nominee of the Depository. This Security is exchangeable for
Securities registered in the name of a Person other than the Depository or its
nominee only in the limited circumstances described in the Indenture, and may
not be transferred except as a whole by the Depository to a nominee of the
Depository, by a nominee of the Depository to the Depository or another nominee
of the Depository or by the Depository or any such nominee to a successor
Depository or a nominee of such a successor Depository.

               Unless and until it is exchanged in whole or in part for Notes in
definitive form, this Note may not be transferred except as a whole by the
Depository to a nominee of the Depository or by a nominee of the Depository to
the Depository or another nominee of the Depository or by the Depository or any
such nominee to a successor Depository or a nominee of such successor
Depository. Unless this certificate is presented by an authorized representative
of The Depository Trust Company (55 Water Street, New York, New York) ("DTC"),
to the issuer or its agent for registration of transfer, exchange or payment,
and any certificate issued is registered in the name of Cede & Co. or such other
name as may be requested by an authorized representative of DTC (and any payment
is made to Cede & Co. or such other entity as may be requested by an authorized
representative of DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR
OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner
hereof, Cede & Co., has an interest herein.

               Capitalized terms used herein shall have the meanings assigned to
them in the Indenture referred to below unless otherwise indicated.

               1.     INTEREST. Iron Mountain Incorporated, a Pennsylvania
corporation (the "COMPANY") promises to pay interest on the principal amount of
this Note at 6-5/8% per annum from June 20, 2003 until January 1, 2016. The
Company shall pay interest, semi-annually in arrears on January 1 and July 1 of
each year, or if any such day is not a Business Day, on the next succeeding
Business Day (each an "INTEREST PAYMENT DATE"). Interest on the Notes will
accrue from the most recent date to which interest has been paid or, if no
interest has been paid, from the date of issuance; PROVIDED that if there is no
existing Default in the payment of interest, and if this Note is authenticated
between a record date referred to on the face hereof and the next succeeding
Interest Payment Date, interest shall accrue from such next succeeding Interest
Payment Date; PROVIDED, FURTHER, that the first Interest Payment Date shall be
January 1, 2004. The Company shall pay interest (including post-petition
interest to the extent allowed in any proceeding under any Bankruptcy Law) on
overdue principal from time to time on demand at a rate equal to the per annum
rate on the Notes then in effect; it shall pay interest (including post-petition
interest to the extent allowed in any proceeding under any Bankruptcy Law) on
overdue installments of interest (without regard to any applicable grace
periods) from time to time on demand at the same rate to the extent lawful.
Interest will be computed on the basis of a 360-day year of twelve 30-day
months.

               2.     METHOD OF PAYMENT. The Company will pay principal,
premium, if any, and interest on the Notes in money of the United States that at
the time of payment is legal tender for payment of public and private debts. The
Company, however, may pay principal, premium, if any, and interest by check
payable in such money. It may mail an interest check to a Holder's registered
address.

               3.     PAYING AGENT, REGISTRAR AND SERVICE AGENT. Initially, The
Bank of New York, the Trustee under the Indenture, will act as Paying Agent,
Registrar and Service Agent. The Notes may be presented for registration of
transfer and exchange at the offices of the Registrar. The Company may change
any Paying Agent, Service Agent or Registrar without notice to any Holder. The
Company or any of its Subsidiaries may act in any such capacity.

<Page>

               4.     INDENTURE. The Company issued the Notes under an Indenture
dated as of December 30, 2002 (the "BASE INDENTURE"), as supplemented by a
Second Supplemental Indenture dated as of June 20, 2003 (the "SUPPLEMENTAL
INDENTURE" and, together with the Base Indenture, the "INDENTURE"), among the
Company, the Guarantors and the Trustee. The terms of the Notes include those
stated in the Indenture and those made part of the Indenture by reference to the
Trust Indenture Act of 1939, as amended (15 U.S. Code Sections 77aaa-77bbbb).
The Notes are subject to all such terms, and Holders are referred to the
Indenture and such Act for a statement of such terms. To the extent any
provision of this Note conflicts with the express provisions of the Indenture,
the provisions of the Indenture shall govern and be controlling. The Notes
issued under the Indenture are subordinated unsecured obligations of the Company
limited to $150,000,000 in aggregate principal amount.

               5.     OPTIONAL REDEMPTION.

               Prior to July 1, 2008, the Notes shall be subject to redemption
at any time at the option of the Company, in whole or in part, upon not less
than 10 nor more than 60 days' notice, at the Make-Whole Price, plus accrued and
unpaid interest, to but excluding the applicable redemption date. On and after
July 1, 2008, the Notes will be subject to redemption at any time at the option
of the Company, in whole or in part, upon not less than 10 nor more than 60
days' notice, at the redemption price (expressed as percentages of principal
amount) set forth below, plus accrued and unpaid interest to but excluding the
applicable redemption date, if redeemed during the twelve-month period beginning
on July 1 of the years indicated below:

<Table>
<Caption>
               YEAR                                               PERCENTAGE
               ----                                               ----------
               <S>                                                  <C>
               2008...........................................      103.313%
               2009...........................................      102.208%
               2010...........................................      101.104%
               2011 and thereafter............................      100.000%
</Table>

               Notwithstanding the foregoing, at any time prior to July 1, 2006
the Company may on any one or more occasions redeem the Notes at a redemption
price of 106.625% of the principal amount thereof, plus accrued and unpaid
interest, and Liquidated Damages if any, to the redemption date, with the net
cash proceeds of one or more Qualified Equity Offerings; provided that (i) at
least $100.0 million in the aggregate principal amount of the Notes (including
any Additional Notes) issued under the Indenture remains outstanding immediately
after the occurrence of such redemption (excluding Notes held by the Company and
the Company's Subsidiaries) and (ii) the redemption must occur within six months
of the date of the closing of any such Qualified Equity Offering.

               6.     NOTICE OF REDEMPTION.

               Notice of redemption will be mailed at least 10 days but not more
than 60 days before the redemption date to each Holder of the Notes to be
redeemed at such Holder's address of record. The Notes in denominations larger
than $1,000 may be redeemed in part but only in integral multiples of $1,000,
unless all the Notes held by a Holder are to be redeemed. In the event of a
redemption of less than all of the Notes, the Notes will be chosen for
redemption by the Trustee in accordance with the Indenture. On and after the
redemption date, interest ceases to accrue on the Notes or portions of them
called for redemption.

               If this Note is redeemed subsequent to a Record Date with respect
to any Interest Payment Date specified above and on or prior to such Interest
Payment Date, then any accrued interest will be paid to the Person in whose name
this Note is registered at the close of business on such Record Date.

<Page>

               7.     MANDATORY REDEMPTION. Except as set forth in paragraph 8
below, the Company shall not be required to repurchase or to make mandatory
redemption payments with respect to the Notes. There are no sinking fund
payments with respect to the Notes.

               8.     REPURCHASE AT OPTION OF HOLDER. This Note is subject to
purchase at the option of the Holder upon the circumstances set forth in
Sections 3.9, 4.17 and 4.18 of the Indenture.

               9.     SUBORDINATION. The payment of the principal of, interest
on or any other amounts due on the Notes is subordinated in right of payment to
all existing and future Senior Debt of the Company, as described in the
Indenture. Each Holder, by accepting a Note, agrees to such subordination and
authorizes and directs the Trustee on its behalf to take such action as may be
necessary or appropriate to effectuate the subordination so provided and
appoints the Trustee as its attorney-in-fact for such purpose.

               10.    DENOMINATIONS, TRANSFER, EXCHANGE. The Notes are in
registered form without coupons in minimum denominations of $1,000 and integral
multiples of $1,000 in excess thereof. The transfer of Notes may be registered
and Notes may be exchanged as provided in the Indenture. The Registrar and the
Trustee may require a Holder, among other things, to furnish appropriate
endorsements and transfer documents and the Company may require a Holder to pay
any taxes and fees required by law or permitted by the Indenture. The Company
need not exchange or register the transfer of any Note or portion of a Note
selected for redemption, except for the unredeemed portion of any Note being
redeemed in part. Also, the Company need not exchange or register the transfer
of any Notes for a period of 15 days before a selection of Notes to be redeemed
or during the period between a record date and the corresponding Interest
Payment Date.

               11.    PERSONS DEEMED OWNERS. The registered Holder of a Note may
be treated as its owner for all purposes.

               12.    AMENDMENT, SUPPLEMENT AND WAIVER. Subject to certain
exceptions, the Indenture with respect to the Notes or the Notes may be amended
or supplemented with the written consent of the Holders of a majority in
principal amount of the Notes and any existing default or compliance with any
provision of the Indenture with respect to the Notes or the Notes may be waived
with the consent of the Holders of a majority in principal amount of the Notes
(including, in each case, Additional Notes, if any). Without the consent of any
Holder of the Notes, the Indenture with respect to the Notes or the Notes may be
amended or supplemented to, in addition to other events more fully described in
the Indenture, cure any ambiguity, defect or inconsistency, provide for
uncertificated Notes in addition to or in place of certificated Notes, provide
for the assumption of the Company's obligations to Holders of the Notes in the
case of a merger or consolidation, make any change that would provide any
additional rights or benefits to the Holders of the Notes or that does not
adversely affect the legal rights under the Indenture of any such Holder, or
comply with requirements of the SEC in order to effect or maintain the
qualification of the Indenture under the TIA.

               13.    DEFAULTS AND REMEDIES. An Event of Default with respect to
the Notes occurs upon the occurrence of any of the following events: the default
for 30 days in the payment when due of interest on the Notes (whether or not
prohibited by the subordination provisions of the Indenture); the default in
payment when due of the principal of or premium, if any, on the Notes (whether
or not prohibited by the subordination provisions of the Indenture); the failure
by the Company to comply with Section 4.18 of the Indenture; the failure by the
Company or any Guarantor for 60 days after written notice from the Trustee or
Holders of not less than 25% of the aggregate principal amount of the Notes
(including Additional Notes, if any) outstanding to comply with any of its other
agreements in the Indenture, Notes or the Subsidiary Guarantees; the default
under any mortgage, indenture or instrument under which there may be issued or
by which there may be secured or evidenced any Indebtedness for money borrowed
by the Company or any of its Restricted Subsidiaries (or the payment of which is

<Page>

guaranteed by the Company or any of its Restricted Subsidiaries) whether such
Indebtedness or guarantee exists on the date of the Indenture or is created
thereafter, if: (i) such default results in the acceleration of such
Indebtedness prior to its express maturity or shall constitute a default in the
payment of such Indebtedness at final maturity of such Indebtedness; and (ii)
the principal amount of any such Indebtedness that has been accelerated or not
paid at maturity, when added to the aggregate principal amount of all other such
Indebtedness that has been accelerated or not paid at maturity, exceeds $10.0
million; the failure by the Company or any of its Restricted Subsidiaries to pay
final judgments aggregating in excess of $10.0 million, which judgments remain
unpaid, undischarged or unstayed for a period of 60 days; certain events of
bankruptcy or insolvency with respect to the Company or any of its Restricted
Subsidiaries that is a Significant Subsidiary; or except as permitted by the
Indenture or the Subsidiary Guarantees, any Subsidiary Guarantee issued by a
Restricted Subsidiary shall be held in any judicial proceeding to be
unenforceable or invalid or shall cease for any reason to be in full force and
effect, or any Restricted Subsidiary or any Person acting on behalf of any
Restricted Subsidiary shall deny or disaffirm in writing its obligations under
its Subsidiary Guarantee.

               If any Event of Default occurs and is continuing, the Trustee or
the Holders of at least 25% in principal amount of the then outstanding Notes
(including Additional Notes, if any) may declare all the Notes to be due and
payable immediately; provided, however, that if any Obligation with respect to
Senior Bank Debt is outstanding pursuant to the Credit Agreement upon a
declaration of acceleration of the Notes, the principal, premium, if any, and
interest on the Notes will not be payable until the earlier of: (1) the day
which is five business days after written notice of acceleration is received by
the Company and the Credit Agent; or (2) the date of acceleration of the
Indebtedness under the Credit Agreement. Notwithstanding the foregoing, in the
case of an Event of Default arising from certain events of bankruptcy or
insolvency with respect to the Company or any Restricted Subsidiary that is a
Significant Subsidiary, the principal of, and premium, if any, and any accrued
and unpaid interest on all outstanding Notes will become due and payable without
further action or notice. In the event of a declaration of acceleration of the
Notes because an Event of Default has occurred and is continuing as a result of
the acceleration of any Indebtedness described in Section 6.1(e) of the
Indenture, the declaration of acceleration of the Notes shall be automatically
annulled if the holders of any Indebtedness described in such section have
rescinded the declaration of acceleration in respect of such Indebtedness within
30 days from the date of such declaration and if: (1) the annulment of the
acceleration of the Notes would not conflict with any judgment or decree of a
competent jurisdiction; and (2) all existing Events of Default, except
non-payment of principal or interest on the Notes that became due solely because
of the acceleration of the Notes, have been cured or waived.

               Subject to certain limitations, Holders of a majority in
principal amount of the then outstanding Notes may direct the Trustee in its
exercise of any trust or power. The Trustee may withhold from Holders of the
Notes notice of any continuing Default or Event of Default (except a Default or
Event of Default relating to the payment of principal or interest) if it
determines that withholding notice is in their interest. The Company is required
to deliver to the Trustee annually a statement regarding compliance with the
Indenture, and the Company is required, upon becoming aware of any Default or
Event of Default, to deliver to the Trustee a statement specifying such Default
or Event of Default and what action the Company is taking or proposes to take
thereto.

               14.    SUBSIDIARY GUARANTEES. Payment of principal of, premium,
if any, and interest (including interest on overdue principal, if any, and
interest, if lawful) on the Notes is guaranteed on an unsecured, senior
subordinated basis by the Guarantors pursuant to Article XII of the Indenture.

               15.    TRUSTEE DEALINGS WITH COMPANY. The Trustee, in its
individual or any other capacity, may make loans to, accept deposits from, and
perform services for the Company or its Affiliates, and may otherwise deal with
the Company or its Affiliates, as if it were not the Trustee.

<Page>

               16.    NO RECOURSE AGAINST OTHERS. No past, present or future
director, officer, employee, incorporator or stockholder, as such, of the
Company or any Guarantor shall have any liability for any obligations of the
Company or any Guarantor under the Notes, the Subsidiary Guarantees or the
Indenture or for any claim based on, in respect of or by reason of such
obligations or their creation. Each Holder by accepting a Note and the related
Subsidiary Guarantees waives and releases all such liability. The waiver and
release are part of the consideration for the issuance of the Notes.

               17.    AUTHENTICATION. This Note shall not be valid until
authenticated by the manual signature of the Trustee or an authenticating agent.

               18.    ABBREVIATIONS. Customary abbreviations may be used in the
name of a Holder or an assignee, such as: TEN COM (= tenants in common), TEN ENT
(= tenants by the entireties), JT TEN (= joint tenants with right of
survivorship and not as tenants in common), CUST (= Custodian), and U/G/M/A (=
Uniform Gifts to Minors Act).

               19.    CUSIP NUMBERS. Pursuant to a recommendation promulgated by
the Committee on Uniform Security Identification Procedures, the Company has
caused CUSIP numbers to be printed on the Notes and the Trustee may use CUSIP
numbers in notices of redemption as a convenience to Holders. No representation
is made as to the accuracy of such numbers either as printed on the Notes or as
contained in any notice of redemption and reliance may be placed only on the
other identification numbers placed thereon.

               The Company shall furnish to any Holder upon written request and
without charge a copy of the Indenture. Requests may be made to:

                      Iron Mountain Incorporated
                      745 Atlantic Avenue
                      Boston, Massachusetts 02111
                      Attention:  Chief Financial Officer

<Page>

                                 ASSIGNMENT FORM

     To assign this Note, fill in the form below: (I) or (we) assign and
transfer this Note to


--------------------------------------------------------------------------------
                  (Insert assignee's soc. sec. or tax I.D. no.)


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


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


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


--------------------------------------------------------------------------------
              (Print or type assignee's name, address and zip code)

and irrevocably appoint
                        --------------------------------------------------------
to transfer this Note on the books of the Company. The agent may substitute
another to act for him.


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


Date:
      ---------

Your Signature:
                 ---------------------------------------------------------------
(Sign exactly as your name appears on the face of this Note)

<Page>

                       OPTION OF HOLDER TO ELECT PURCHASE

               If you want to elect to have this Note purchased by the Company
pursuant to Section 4.17 or 4.18 of the Indenture, check the box below:

                             / /    Section 4.17

                             / /    Section 4.18

          If you want to elect to have only part of the Note purchased by the
Company pursuant to Section 4.17 of the Supplemental Indenture, state the amount
you elect to have purchased: $
                               ---------


Date:                 Your Signature:
     ---------                        ----------------------------------------
                      (Sign exactly as your name appears on the Note)

                      Tax Identification No.:
                                             ---------------------------------

<Page>

                         SCHEDULE OF EXCHANGES OF NOTES*


               The following exchanges of a part of this Global Note for other
Notes have been made:

<Table>
<Caption>
                                                                   Principal Amount of
                          Amount of              Amount of          this Global Note        Signature of
                         decrease in            increase in          following such       authorized office
                      Principal Amount        Principal Amount        decrease (or          of Trustee or
 Date of Exchange    of this Global Note    of this Global Note         increase)           Service Agent
-----------------    -------------------    -------------------    -------------------    -----------------
<S>                  <C>                    <C>                    <C>                    <C>



</Table>

----------
*This schedule should be included only if the Note is issued in global form.

<Page>

                                    EXHIBIT B

       FORM OF SUPPLEMENTAL INDENTURE TO BE DELIVERED BY FUTURE GUARANTORS

               SUPPLEMENTAL INDENTURE (this "SUPPLEMENTAL INDENTURE"), dated as
of ________________, _____, among _______________ (the "GUARANTEEING
SUBSIDIARY"), a subsidiary of Iron Mountain Incorporated (or its successor), a
Pennsylvania corporation (the "COMPANY"), the Company, and The Bank of New York,
a New York banking corporation, as trustee under the Indenture referred to below
(the "TRUSTEE").

                               W I T N E S S E T H

               WHEREAS, the Company has heretofore executed and delivered to the
Trustee an indenture, dated as of December 30, 2002, as supplemented by the
Second Supplemental Indenture, dated as of June 20, 2003 (the indenture, as so
supplemented, the "INDENTURE") providing for the issuance of an aggregate
principal amount of up to $150,000,000 of 6-5/8% Senior Subordinated Notes due
2016 (the "NOTES");

               WHEREAS, the Indenture provides that under certain circumstances
the Guaranteeing Subsidiary shall execute and deliver to the Trustee a
supplemental indenture pursuant to which the Guaranteeing Subsidiary shall
unconditionally guarantee all of the Company's obligations under the Notes and
the Indenture on the terms and conditions set forth herein (the "NOTE
GUARANTEE"); and

               WHEREAS, pursuant to Section 9.1 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

               NOW THEREFORE, in consideration of the foregoing and for other
good and valuable consideration, the receipt of which is hereby acknowledged,
the Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the
equal and ratable benefit of the Holders of the Notes as follows:

               1.     CAPITALIZED TERMS. Capitalized terms used herein without
definition shall have the meanings assigned to them in the Indenture.

               2.     AGREEMENT TO GUARANTEE. The Guaranteeing Subsidiary hereby
agrees that its obligations to the Holder and the Trustee pursuant to this
Subsidiary Guarantee shall be as expressly set forth in Article XII of the
Indenture and in such other provisions of the Indenture as are applicable to the
Guarantors (including, without limitation, Article XIII of the Indenture), and
reference is made to the Indenture for the precise terms of this Supplemental
Indenture. The terms of Article XII of the Indenture and such other provisions
of the Indenture (including, without limitation, Article XIII of the Indenture)
as are applicable to the Guarantors are incorporated herein by reference.

               3.     EXECUTION AND DELIVERY OF SUBSIDIARY GUARANTEES.

                      (a)     If an Officer whose signature is on this
Supplemental Indenture no longer holds that office at the time the Trustee
authenticates the Note, the Subsidiary Guarantee shall be valid nevertheless.

                      (b)     The delivery of any Note by the Trustee, after the
authentication thereof under the Indenture, shall constitute due delivery of the
Subsidiary Guarantee set forth in this Supplemental Indenture on behalf of the
Guaranteeing Subsidiary.

               4.     NO RECOURSE AGAINST OTHERS. No past, present or future
director, officer, employee, incorporator or stockholder of the Guaranteeing
Subsidiary, as such, shall have any liability for

<Page>

any obligations of the Company or any Guarantor (including the Guaranteeing
Subsidiary) under the Notes, any Subsidiary Guarantee, the Indenture or this
Supplemental Indenture or for any claim based on, in respect of, or by reason
of, such obligations or their creation. Each Holder of the Notes by accepting a
Note waives and releases all such liability. The waiver and release are part of
the consideration for issuance of the Notes.

               5.     NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF
NEW YORK SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT
WITHOUT GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT
THAT THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED
THEREBY.

               6.     COUNTERPARTS. The parties may sign any number of copies of
this Supplemental Indenture. Each signed copy shall be an original, but all of
them together represent the same agreement.

               7.     EFFECT OF HEADINGS. The Section headings herein are for
convenience only and shall not affect the construction hereof.

               8.     THE TRUSTEE. The Trustee shall not be responsible in any
manner whatsoever for or in respect of the validity or sufficiency of this
Supplemental Indenture or for or in respect of the recitals contained herein,
all of which recitals are made solely by the Guaranteeing Subsidiary and the
Company.

<Page>

               IN WITNESS WHEREOF, the parties hereto have caused this
Supplemental Indenture to be duly executed and attested, all as of the date
first above written.

               Dated: _______________, 20___

                                           [GUARANTEEING SUBSIDIARY]

                                           By:
                                              -----------------------------
                                           Name:
                                           Title:

                                           [COMPANY]

                                           By:
                                              -----------------------------
                                           Name:
                                           Title:

                                           [TRUSTEE],
                                           as Trustee

                                           By:
                                              -----------------------------
                                               Authorized Signatory