<Page> Exhibit 10.1 EXECUTION VERSION FIRST AMENDMENT FIRST AMENDMENT, dated as of July 9, 2003 (the "AMENDMENT"), to the Fifth Amended and Restated Credit Agreement, dated as of March 15, 2002 (as amended, the "CREDIT AGREEMENT"), among IRON MOUNTAIN INCORPORATED, a Pennsylvania corporation (the "COMPANY"), IRON MOUNTAIN CANADA CORPORATION (formerly known as Pierce Leahy Canada Company), a company organized under the laws of the Province of Nova Scotia, the several banks and other financial institutions or entities from time to time parties to the Credit Agreement (the "LENDERS"), FLEET NATIONAL BANK, as documentation agent, J.P. MORGAN SECURITIES INC., as arranger and book manager, J.P. MORGAN BANK CANADA, as Canadian Administrative Agent, and JPMORGAN CHASE BANK, as administrative agent for the Lenders (in such capacity, the "ADMINISTRATIVE AGENT"). W I T N E S S E T H: WHEREAS, the Company has requested that the Lenders and the Administrative Agent agree to the amendments to the Credit Agreement set forth below, and the Lenders parties hereto and the Administrative Agent agree to such amendments upon the terms set forth herein; NOW, THEREFORE, in consideration of the respective covenants and agreements set forth herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto hereby agree as follows: 1. DEFINED TERMS. Unless otherwise defined herein, all capitalized terms used herein shall have the meanings given to them in the Credit Agreement. 2. AMENDMENTS TO SECTION 9.24 (INVESTMENTS IN EXCLUDED SUBSIDIARIES). Section 9.24 is hereby amended to read in its entirety as follows: "The Company will not, and will not permit any of its Subsidiaries (other than its Excluded Subsidiaries), to make any advance, loan or other extension of credit to, or any other Investment in, or Guarantee any Indebtedness of, any Excluded Subsidiary or any other person organized outside of the United States or principally conducting its business outside the United States if, after giving effect thereto, the aggregate outstanding amount of such Investments and Guaranties (other than (a) Guaranties permitted under clause (viii) of the definition of "Permitted Indebtedness" in Section 1.01 hereof, (b) the Guaranties by the Company and its Subsidiaries of (x) the Pierce 1998 Senior Notes and (y) Indebtedness under the Canadian Commitments, and (c) Investments by the Company in Iron Mountain Canada Corporation to finance the payment by Iron Mountain Canada Corporation of principal, interest and other amounts due in respect of the Pierce 1998 Senior Notes) made after July 9, 2003 is greater than $400,000,000 (with the applicable exchange rate for any Investment or Guaranty or repayment thereof determined by reference to the relevant Exchange Rate in effect at the time of such Investment or Guaranty or repayment)." <Page> 3. AMENDMENT TO SECTION 11 (THE ADMINISTRATIVE AGENT). J.P. Morgan Bank Canada hereby resigns as Canadian Administrative Agent and the Majority Lenders, in consultation with the Company, hereby appoint JPMorgan Chase Bank, Toronto Branch, as its successor. JPMorgan Chase Bank, Toronto Branch hereby accepts such appointment as Canadian Administrative Agent. As of the Effectiveness Date, as defined below, all provisions of the Credit Agreement, including but not limited to Section 11 thereof, shall apply to JPMorgan Chase Bank, Toronto Branch, upon the same terms and subject to the same conditions as provided in Section 11 thereof, MUTATIS MUTANDIS. This Section 3 of the Amendment shall become effective immediately upon receipt of the signature pages executed by the Majority Lenders and the Company, without regard to the other conditions precedent set forth in Section 6 hereof. 4. AMENDMENT TO SECTION 12.02 (NOTICES). Section 12.02 is hereby amended by deleting the Address for Notices with regard to the Canadian Administrative Agent referred to therein and replacing it in its entirety with the information contained in Exhibit A hereto. 5. REPRESENTATIONS AND WARRANTIES. On and as of the date hereof, the Company hereby confirms, reaffirms and restates the representations and warranties set forth in Section 8 of the Credit Agreement MUTATIS MUTANDIS, except to the extent that such representations and warranties expressly relate to a specific earlier date in which case the Borrower hereby confirms, reaffirms and restates such representations and warranties as of such earlier date. 6. EFFECTIVENESS. This Amendment shall become effective immediately upon: (i) execution by the Majority Lenders and the Company and (ii) the payment by the Company to the Administrative Agent, on behalf of each Lender that executes and delivers a counterpart of this Amendment, of an amendment fee in an amount equal to 0.05% of each such Lender's Commitment (the "EFFECTIVENESS DATE"). 7. VALID AND BINDING. This Amendment shall be binding upon and inure to the benefit of each of the parties hereto and their respective successors and assigns. 8. PAYMENT OF EXPENSES. The Company agrees to pay or reimburse the Administrative Agent for all out-of-pocket costs and expenses incurred in connection with the Amendment, any other documents prepared in connection herewith and the transactions contemplated hereby, including, without limitation, the reasonable fees and disbursements of counsel. 9. REFERENCE TO AND EFFECT ON THE CREDIT AGREEMENT; LIMITED EFFECT. On and after the date hereof and the satisfaction of the conditions contained in this Amendment, each reference in the Credit Agreement to "this Agreement", "hereunder", "hereof" or words of like import referring to the Credit Agreement shall mean and be a reference to the Credit Agreement as amended hereby. The execution, delivery and effectiveness of this Amendment shall not, except as expressly provided herein, operate as a waiver of any right, power or remedy of any Lender under the Credit Agreement, nor constitute a waiver of any provisions of the Credit Agreement. Except as expressly amended herein, all of the provisions and covenants of the Credit Agreement are and shall continue to remain in full force and effect in accordance with the terms thereof and are hereby in all respects ratified and confirmed. 2 <Page> 10. GOVERNING LAW. THIS AMENDMENT SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, AND THE RIGHTS OF THE PARTIES SHALL BE GOVERNED BY, THE LAW OF THE STATE OF NEW YORK. 11. COUNTERPARTS. This Amendment may be executed by one or more of the parties hereto in any number of separate counterparts (which may include counterparts delivered by facsimile transmission) and all of said counterparts taken together shall be deemed to constitute one and the same instrument. Any executed counterpart delivered by facsimile transmission shall be effective as for all purposes hereof. 3 <Page> IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed and delivered by their proper and duly authorized officers as of the day and year first above written. IRON MOUNTAIN INCORPORATED By: /s/ John F. Kenny, Jr. ----------------------- Name: John F. Kenny, Jr. Title: EVP & CFO 4 <Page> JPMORGAN CHASE BANK, as Administrative Agent By: /s/ Robert T. Sacks -------------------- Name: Robert T. Sacks Title: Managing Director JPMORGAN CHASE BANK, as a Lender By: /s/ Robert T. Sacks -------------------- Name: Robert T. Sacks Title: Managing Director 5 <Page> J.P. MORGAN BANK CANADA as former Canadian Administrative Agent, By: /s/ Christine Chan ------------------- Name: Christine Chan Title: Vice President 6 <Page> JPMORGAN CHASE BANK, TORONTO BRANCH as new Canadian Administrative Agent and as a Lender, By: /s/ Christine Chan ------------------- Name: Christine Chan Title: Vice President 7 <Page> AERIES FINANCE-II LTD. By:INVESCO Senior Secured Management, Inc. As Sub-Managing Agent By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 8 <Page> AIM FLOATING RATE FUND By:INVESCO Senior Secured Management, Inc. As Attorney in fact By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 9 <Page> AIMCO CDO Series 2000-A By: /s/ --------------------- Name: Title: By: /s/ --------------------- 10 <Page> AIMCO CLO Series 2001-A By: /s/ --------------------- Name: Title: By: /s/ --------------------- 11 <Page> ALLSTATE LIFE INSURANCE COMPANY By: /s/ --------------------- Name: Title: By: /s/ --------------------- 12 <Page> APEX (IDM) CDO I, LTD. ---------------------- ELC (CAYMAN) LTD. 2000-I ------------------------ By: David L. Babson & Company Inc. as Collateral Manager By: /s/ Adrienne Musgnug --------------------- Name: Adrienne Musgnug Title: Managing Director MAPLEWOOD (CAYMAN) LIMITED -------------------------- By: David L. Babson & Company Inc. under delegated authority from Massachusetts Mutual Life Insurance Company as Investment Manager By: /s/ Adrienne Musgnug --------------------- Name: Adrienne Musgnug Title: Managing Director SIMSBURY CLO, LIMITED --------------------- By: David L. Babson & Company Inc. under delegated authority from Massachusetts Mutual Life Insurance Company as Investment Manager By: /s/ Adrienne Musgnug --------------------- Name: Adrienne Musgnug Title: Managing Director MASSACHUSETTS MUTUAL LIFE INSURANCE COMPANY ----------------- By: David L. Babson & Company Inc. Insurance as Investment Manager By: /s/ Adrienne Musgnug --------------------- Name: Adrienne Musgnug Title: Managing Director 13 <Page> APEX (Trimaran) CDO I, LTD. By Trimaran Advisors, L.L.C. By: /s/ David M. Millison ---------------------- Name: David M. Millison Title: Managing Director 14 <Page> ARAB BANK plc By: /s/ Thomas J. Butler --------------------- Name: Thomas J. Butler Title: Senior Vice President 15 <Page> AVALON CAPITAL LTD. By: INVESCO Senior Secured Management, Inc. As Portfolio Advisor By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 16 <Page> AVALON CAPITAL LTD. 2 By: INVESCO Senior Secured Management, Inc. As Portfolio Advisor By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 17 <Page> BALLYROCK CDO I Limited, By: BALLYROCK Investment Advisors LLC, as Collateral Manager By: /s/ Lisa Rymut --------------- Name: Lisa Rymut Title: Assistant Treasurer 18 <Page> The Bank of New York By: /s/ Kenneth P. Sneider ----------------------- Name: Kenneth P. Sneider Title: Vice President 19 <Page> The Bank of Nova Scotia By: /s/ Todd S. Meller ------------------- Name: Todd S. Meller Title: Managing Director 20 <Page> Bank One, NA By: /s/ William Buhr ----------------- Name: William Buhr Title: Associate 21 <Page> BEAR STEARNS CORPORATE LENDING INC. By: /s/ Lawrence Alletto --------------------- Name: Lawrence Alletto Title: Authorized Signatory 22 <Page> BIG SKY SENIOR LOAN FUND, LTD. By: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ --------------------- Name: Title: Vice President 23 <Page> Carlyle High Yield Partners II, Ltd. By: /s/ Mark Alter --------------- Name: Mark Alter Title: Managing Director 24 <Page> Carlyle High Yield Partners III, Ltd. By: /s/ Mark Alter --------------- Name: Mark Alter Title: Managing Director 25 <Page> Carlyle High Yield Partners IV, Ltd. By: /s/ Mark Alter --------------- Name: Mark Alter Title: Managing Director 26 <Page> CHARTER VIEW PORTFOLIO By: INVESCO Senior Secured Management, Inc. As Investment Advisor By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 27 <Page> CIBC Inc. By: /s/ Lindsay Gordon ------------------- Name: Lindsay Gordon Title: Executive Director CIBC World Markets Corp. As Agent 28 <Page> Citizens Bank of Massachusetts By: /s/ Amy D. Faber ----------------- Name: Amy D. Faber Title: Loan Officer 29 <Page> COSTANTINUS EATON VANCE CDO V, LTD. BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------ Name: Title: Vice President 30 <Page> Credit Lyonnais New York Branch By: /s/ Scott R. Chappelka ----------------------- Name: Scott R. Chappelka Title: Vice President 31 <Page> DIVERSIFIED CREDIT PORTFOLIO LTD. By: INVESCO Senior Secured Management, Inc. As Investment Advisor By: /s/ Thomas H.B. Ewald ----------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 32 <Page> Dresdner Bank AG - New York and Grand Cayman By: /s/ Erika P. Walters-Engemann & Richard Filippi ------------------------------------------------ Name: Erika P. Walters-Engemann & Richard Filippi Title: Director & Vice President 33 <Page> EATON VANCE CDO III, LTD. BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 34 <Page> EATON VANCE CDO IV, LTD. BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 35 <Page> EATON VANCE SENIOR INCOME TRUST BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 36 <Page> EATON VANCE INSTITUTIONAL SENIOR LOAN FUND BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 37 <Page> ERSTE BANK, NEW YORK BRANCH By: /s/ Gregory T. Aptman ---------------------- Name: Gregory T. Aptman Title: Vice President By: /s/ Bryan Lynch ---------------- Name: Bryan Lynch Title: First Vice President 38 <Page> Fidelity Advisor Series II: Fidelity Advisor Floating Rate High Income Fund By: /s/ John H. Costello --------------------- Name: John H. Costello Title: Assistant Treasurer 39 <Page> Fleet National Bank By: /s/ Michael A. Palmer ----------------------- Name: Michael A. Palmer Title: Senior Vice President 40 <Page> General Electric Capital Corporation By: /s/ Robert M. Kadlick ----------------------- Name: Robert M. Kadlick Title: Duly Authorized Signatory 41 <Page> GRAYSON & CO BY: BOSTON MANAGEMENT AND RESEARCH AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 42 <Page> Gulf Stream-Compass CLO 2002-1, Ltd. By: Gulf Stream Asset Management, LLC, as collateral manager By: /s/ Barry K. Love ------------------- Name: Barry K. Love Title: Chief Credit Officer 43 <Page> HARBOUR TOWN FUNDING LLC By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Assistant Vice President 44 <Page> HSBC Bank USA By: /s/ Renata E. Szirmai ---------------------- Name: Renata E. Szirmai Title: Vice President 45 <Page> ING PRIME RATE TRUST By: ING Investments, LLC as its investment manager By: /s/ Brian S. Horton -------------------- Name: Brian S. Horton Title: Vice President 46 <Page> ING SENIOR INCOME FUND By: ING Investments, LLC as its investment manager By: /s/ Brian S. Horton -------------------- Name: Brian S. Horton Title: Vice President 47 <Page> INVESCO CBO 2000-1 LTD. By: INVESCO Senior Secured Management, Inc. as Portfolio Advisor By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 48 <Page> JUPITER FUNDING TRUST By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Authorized Agent 49 <Page> JUPITER LOAN FUNDING LLC By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Assistant Vice President 50 <Page> KATONAH I, LTD. By: /s/ Ralph Della Rocca ---------------------- Name: Ralph Della Rocca Title: Authorized Officer Katonah Capital, L.L.C., As Manager 51 <Page> KATONAH III, LTD. By: /s/ Ralph Della Rocca ---------------------- Name: Ralph Della Rocca Title: Authorized Officer Katonah Capital, L.L.C., As Manager 52 <Page> LAGUNA FUNDING TRUST By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Authorized Agent 53 <Page> Madison Avenue CDO I, Ltd. By: Metropolitan Life Insurance Company as Collateral Manager By: /s/ James R. Dingler --------------------- Name: James R. Dingler Title: Director 54 <Page> Mariner CDO 2002, Ltd. By: /s/ ------------------------- Name: Title: 55 <Page> Metropolitan Life Insurance Company By: /s/ James R. Dingler --------------------- Name: James R. Dingler Title: Director 56 <Page> ML CLO XV PILGRIM AMERICA (CAYMAN) LTD. By: ING Investments, LLC as its investment manager By: /s/ Brian S. Horton -------------------- Name: Brian S. Horton Title: Vice President 57 <Page> OASIS COLLATERALIZED HIGH INCOME PORTFOLIOS-1 LTD. By: INVESCO Senior Secured Management, Inc. as Subadvisor By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 58 <Page> OLYMPIC FUNDING TRUST, SERIES 1999-1 By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Authorized Agent 59 <Page> OXFORD STRATEGIC INCOME FUND BY: EATON VANCE MANAGEMENT AS INVESTMENT ADVISOR By: /s/ ------------------------- Name: Title: Vice President 60 <Page> PPM SHADOW CREEK FUNDING LLC By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Assistant Vice President 61 <Page> PPM SPYGLASS FUNDING TRUST By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Authorized Agent 62 <Page> The Prudential Insurance Company of America By: Prudential Investment Management, Inc. as Investment Advisor By: /s/ Jill Brown --------------- Name: Jill Brown Title: Vice President 63 <Page> PUTNAM DIVERSIFIED INCOME TRUST By: /s/ Beth Mazor --------------- Name: Beth Mazor Title: V.P. 64 <Page> Sankaty Advisors, LLC as Collateral Manager for Castle Hill II - INGOTS, Ltd., as Term Lender By: /s/ Diane J. Exter ------------------- Name: Diane J. Exter Title: Managing Director Portfolio Manager 65 <Page> Sankaty Advisors, LLC as Collateral Manager for Great Point CLO 1999-1 Ltd., as Term Lender By: /s/ Diane J. Exter ------------------- Name: Diane J. Exter Title: Managing Director Portfolio Manager 66 <Page> Sankaty Advisors, LLC as Collateral Manager for Race Point CLO, Limited, as Term Lender By: /s/ Diane J. Exter ------------------- Name: Diane J. Exter Title: Managing Director Portfolio Manager 67 <Page> Sankaty High Yield Partners III, L.P. By: /s/ Diane J. Exter ------------------- Name: Diane J. Exter Title: Managing Director Portfolio Manager 68 <Page> SARATOGA CLO I, LIMITED By: INVESCO Senior Secured Management, Inc. as Asset Manager By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 69 <Page> SAWGRASS TRADING LLC By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Assistant Vice President 70 <Page> Seaboard CLO 2000 Ltd. By: ORIX Capital Markets, LLC Its Collateral Manager By: /s/ Sheppard H.C. Davis, Jr. ----------------------------- Name: Sheppard H.C. Davis, Jr. Title: Managing Director 71 <Page> SENIOR DEBT PORTFOLIO By: Boston Management and Research as Investment Advisor By: /s/ ---------------------- Name: Title: Vice President 72 <Page> SEQUILS-Glace Bay, Ltd. By Royal Bank of Canada as Collateral Manager By: /s/ Melissa Marano ------------------- Name: Melissa Marano Title: Partner 73 <Page> SEQUILS-LIBERTY, LTD. By: INVESCO Senior Secured Management, Inc. as Collateral Manager By: /s/ Thomas H.B. Ewald ---------------------- Name: Thomas H.B. Ewald Title: Authorized Signatory 74 <Page> The Sumitomo Trust & Bank Co., Ltd., New York Branch By: /s/ Elizabeth A. Quirk ----------------------- Name: Elizabeth A. Quirk Title: Vice President 75 <Page> TORONTO DOMINION (NEW YORK), INC. By: /s/ Stacey Malek ----------------- Name: Stacey Malek Title: Vice President 76 <Page> UNION BANK of CALIFORNIA, N.A. By: /s/ Albert W. Kelley --------------------- Name: Albert W. Kelley Title: Vice President 77 <Page> VAN KAMPEN CLO II, LIMITED By: Van Kampen Investment Advisory Corp. as Collateral Manager By: /s/ Darvin D. Pierce --------------------- Name: Darvin D. Pierce Title: Executive Director 78 <Page> VAN KAMPEN SENIOR INCOME TRUST By: Van Kampen Investment Advisory Corp. By: /s/ Darvin D. Pierce --------------------- Name: Darvin D. Pierce Title: Executive Director 79 <Page> WACHOVIA BANK, NATIONAL ASSOCIATION By: /s/ Michael Romanzo -------------------- Name: Michael Romanzo Title: Vice President 80 <Page> Webster Bank By: /s/ Carolyn Natale ------------------- Name: Carolyn Natale Title: Vice President 81 <Page> WINGED FOOT FUNDING TRUST By: /s/ Ann E. Morris ------------------ Name: Ann E. Morris Title: Authorized Agent 82 <Page> EXHIBIT A NOTICE INFORMATION / WIRING INSTRUCTIONS AGENT: JPMORGAN CHASE BANK , TORONTO BRANCH ADDRESS: 200 Bay Street, Suite 1800 Royal Bank Plaza, South Tower Toronto, Ontario M5J 2J2 CREDIT CONTACT: Christine Chan Vice President Telephone: (416) 981-9123 Facsimile: (416) 981-9138 E-mail: Christine.Chan@jpmorgan.com ADMINISTRATIVE CONTACT: Amanda Staff / Ramona Sankar Corporate Banking Officer Telephone: (416) 981-9235 / (416) 981-9144 Facsimile: (416) 981-9128 E-mail: Amanda.Staff@jpmorgan.com / Ramona K Sankar@jpmorgan.com PAYMENTS TO BE MADE AS FOLLOWS: CANADIAN DOLLARS ROYAL BANK OF CANADA CORRESPONDENT BKG DIVISION, TORONTO TRANSIT #: 07172 F/A: JPMORGAN CHASE BANK, TORONTO BRANCH A/C #: 1000405 U.S. DOLLARS JPMORGAN CHASE BANK, NEW YORK SWIFT: CHASUS33 ABA: 021000021 F/A: JPMORGAN CHASE BANK, TORONTO BRANCH A/C #: 400929821