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                                                                    Exhibit 10.5

                              EMPLOYMENT AGREEMENT

          EMPLOYMENT AGREEMENT, dated as of February 1, 2004 (the "Commencement
Date"), by and between CommVault Systems Inc., a Delaware corporation, with its
principal office at 2 Crescent Place, Oceanport, NJ, 07757 (the "Company"), and
N. ROBERT HAMMER residing at 23 Bay Harbor Road, Tequesta, FL 33469
("Executive").

          WHEREAS, the Company desires to continue to employ Executive as
Chairman, President and Chief Executive Officer of the Company, and

          WHEREAS, Executive desires to enter into this agreement (the
"Agreement") as to the terms of his employment by the Company and his position
with the Company.

          NOW, THEREFORE, in consideration of the promises and mutual covenants
contained herein and for other good and valuable consideration, the parties
agree as follows:

          1. Term of Employment. Except for earlier termination as provided in
Section 7 hereof, Executive's employment under this Agreement shall be for a
term commencing on the Commencement Date and ending on March 31, 2005 (the
"Initial Term"). Subject to Section 7 hereof, the Initial Term shall be
automatically extended for additional terms of successive one (1) year periods
(the "Additional Term") unless the Company or Executive gives written notice to
the other at least thirty (30) days prior to


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the expiration of the Initial Term or the then current Additional Term of the
termination of Executive's employment hereunder at the end of such current term.
(The Initial Term and any Additional Term(s) shall hereinafter be referred to as
the "Employment Term".)

          2. Positions. (a) Executive shall continue to serve as the Chairman,
President and Chief Executive Officer of the Company. If requested by the Board
of Directors of the Company (the "Board"), the Executive shall also serve as an
executive officer or director of subsidiaries and a director of associated
companies of the Company without additional compensation and subject to any
policy of the Compensation Committee of the Board (the "Compensation Committee")
with regard to retention or turnover of the director's fees.

          (b) Executive shall report to the Board and shall have such duties and
authority consistent with his then position as shall be assigned to him from
time to time by the Board.

          (c) During the Employment Term, Executive shall devote substantially
all of his business time and efforts to the performance of his duties hereunder
and use his best efforts in such endeavors; provided, however, that Executive
shall be allowed, to the extent that such activities do not materially interfere
with the performance of his duties and responsibilities hereunder, to manage his
passive personal investments and to serve on corporate, civic, or charitable
boards or committees. Notwithstanding the foregoing, the Executive shall not
serve on any corporate board of directors if such service would be inconsistent
with his fiduciary responsibilities to the Company and in no event shall
Executive serve on any such board unless approved in writing by the Board.


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          3. Base Salary. During the Employment Term, the Company shall pay
Executive a base salary at the annual rate of $300,000. Base salary shall be
payable in accordance with the usual payroll practices of the Company.
Executive's Base Salary shall be subject to annual review by the Board. The base
salary as determined as aforesaid from time to time shall constitute "Base
Salary" for purposes of this Agreement.

          4. Incentive Compensation. For each fiscal year or portion thereof
during the Employment Term, Executive shall be eligible to participate in an
annual bonus plan of the Company in accordance with, and subject to the terms
of, such plan, that provides an annualized cash bonus opportunity with a target
bonus potential equal to a percentage of Base Salary (the "Target Bonus").

          5. Employee Benefits and Vacation. (a) During the Employment Term,
Executive shall be entitled to participate in all retirement, savings, incentive
compensation, welfare and other employee benefit plans and arrangements and
fringe benefits and perquisites generally maintained by the Company from time to
time for the benefit of executives of the Company, in accordance with their
respective terms as in effect from time to time (other than any special
arrangement entered into with an executive).

          (b) During the Employment Term, Executive shall be entitled to
vacation each year in accordance with the Company's policies in effect from time
to time, but in no event less than three (3) weeks paid vacation per calendar
year. The Executive shall also be entitled to such periods of sick leave as is
customarily provided by the Company for its senior executive employees.


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          6. Business Expenses. The Company shall reimburse Executive for the
travel, entertainment and other business expenses incurred by Executive in the
performance of his duties hereunder, in accordance with the Company's policies
as in effect from time to time.

          7. Termination. (a) The employment of Executive under this Agreement
shall terminate upon the occurrence of any of the following events:

               (i) the death of the Executive;

               (ii) the termination of the Executive's employment by the Company
          due to the Executive's Disability pursuant to Section 7(b) hereof;

               (iii) the termination of the Executive's employment by the
          Company without Cause or by the Company in accordance with Section 1
          hereof;

               (iv) the termination of the Executive's employment by the Company
          for Cause pursuant to Section 7(c) hereof;

               (v) the retirement of the Executive by the Company at or after
          his sixty-fifth (65th) birthday to the extent such termination is
          specifically permitted as a stated exception from applicable federal
          and state age discrimination laws based on position and retirement
          benefits.

          (b) Disability. If, by reason of the same or related physical or
mental reasons, Executive is unable to carry out his material duties pursuant to
this Agreement for more than six (6) months in any twelve (12) consecutive month
period, the Company


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may terminate Executive's employment for Disability upon thirty (30) days prior
written notice, by a Notice of Disability Termination, at any time thereafter
during such twelve (12) month period in which Executive is unable to carry out
his duties as a result of the same or related physical or mental illness. Such
termination shall not be effective if Executive returns to the full time
performance of his material duties within such thirty (30) day notice period. If
Executive is eligible for disability payments prior to said termination under
any disability plan sponsored by the Company, his Base Salary shall be reduced
by the amount of such disability payments.

          (c) Cause. Subject to the notification provisions of Section 7(d)
below, Executive's employment hereunder may be terminated by the Company for
Cause. For purposes of this Agreement, the term "Cause" shall be limited to (i)
willful misconduct by Executive with regard to the business, assets or employees
of the Company; (ii) the refusal or willful failure of Executive to follow the
proper written direction of the Board, provided that the foregoing refusal or
willful failure shall not be "Cause" if Executive in good faith believes that
such direction is illegal and promptly so notifies the Board; (iii) continuing
refusal or willful failure by the Executive to perform the duties required of
him hereunder (other than any such failure resulting from incapacity due to
physical or mental illness) after a written demand for substantial performance
is delivered to the Executive by the Board which specifically identifies the
manner in which it is believed that the Executive has substantially and
continually refused to perform his duties hereunder; (iv) the Executive pleading
nolo contendere or guilty to, or being convicted of, a felony (other than a
traffic infraction); (v) the breach by Executive of any fiduciary duty owed by
Executive to the Company; (vi) your abuse of alcohol or drugs (legal or


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illegal) that, in the Board's sole and absolute judgment, is deemed to
materially impair your ability to perform your duties hereunder; or (vii)
Executive's dishonesty, misappropriation or fraud with regard to the Company
(other than good faith expense account disputes).

          (d) Notice of Termination for Cause. A Notice of Termination for Cause
shall mean a notice that shall indicate the specific termination provision in
Section 7(c) relied upon and shall set forth in reasonable detail the facts and
circumstances which provide for a basis for Termination for Cause. The date of
termination for a Termination for Cause shall be the date indicated in the
Notice of Termination. Any purported Termination for Cause which is held by a
court not to have been based on the grounds set forth in this Agreement or not
to have followed the procedures set forth in this Agreement shall be deemed a
Termination by the Company without Cause.

          (e) Good Reason. For purposes of this agreement, for "Good Reason"
means a termination of employment by Executive effected by written notice of
termination given within sixty (60) days after the occurrence of any of the
following events: (i) any material diminution of Executive's positions, duties,
responsibilities or scope of duties or responsibilities; (ii) a material
diminution in the total compensation (i.e. salary, bonus and benefits) provided
by the Company to Executive; or (iii) a material relocation by the Company of
Executive's principal office from the location of such office at the time of the
Change in Control.


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          8. Consequences of Termination of Employment. (a) Death. If
Executive's employment is terminated during the Employment Term by reason of
Executive's death, the employment period under this Agreement shall terminate
without further obligations to the Executive's legal representatives under this
Agreement or otherwise except for: (i) any compensation earned but not yet paid,
including without limitation, any declared but unpaid bonus for the prior fiscal
year, any amount of Base Salary earned but unpaid, any accrued vacation pay
payable pursuant to the Company's policies and any unreimbursed business
expenses payable pursuant to Section 6, which amounts shall be promptly paid in
a lump sum to Executive's estate; and (ii) any other amounts or benefits owing
to Executive under the then applicable employee benefit plans, long term
incentive plans and programs or equity plans of the Company, which shall be paid
in accordance with such plans and programs.

          (b) Disability. If Executive's employment, pursuant to this Agreement,
is terminated by reason of Executive's Disability, Executive shall be entitled
to receive the payments and benefits to which his representatives would be
entitled in the event of a termination of employment by reason of his death
(other than life insurance benefits). Executive shall thereafter be eligible for
disability benefits and entitlements, if any, pursuant to the Company's Human
Resource policies and employee benefit programs.

          (c) Termination by the Company without Cause or by Nonextension of
Employment Term. If (i) Executive's employment with the Company is terminated by
the Company without Cause or (ii) by the Company pursuant to Section 1 hereof
(except as provided in Section 7(a)(v) hereof), the Company shall have no
further obligations to the Executive under this Agreement or otherwise, except
that, subject to


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Sections 8(e), 9, and 11 hereof, Executive shall be entitled to receive (A)
either equal bi-weekly payments or a lump sum payment, at the Company's
discretion, of an amount equal to one-twenty sixth of Executive's then Base
Salary, but off the employee payroll, for a period of twelve (12) months
following the date of his termination, (B) within five (5) days after such
termination (i) any unreimbursed business expenses payable pursuant to Section
6; and (ii) any Base Salary through the date of termination, and accrued
vacation pay payable pursuant to the Company's policies; (C) any other amounts
or benefits previously accrued on behalf of the Executive under the then
applicable employee benefit plans, incentive plans or programs of the Company
and paid in accordance with such plans and programs; any vested benefit pursuant
to any Company equity plans and paid in accordance with such plans and programs;
(D) payment by the Company of the premiums for the Executive and his dependents
health coverage for twelve (12) months under the Company's health plans which
cover the senior executives of the Company or materially similar benefits.
Payments under (D) above may at the discretion of the Company be made by
continuing participation of Executive in the plan as a terminee, by paying the
applicable COBRA premium for Executive and his dependents, or by covering
Executive and his dependents under substitute arrangements; and (E)
notwithstanding anything to the contrary contained in (a) any option or similar
agreement between Executive and the Company or (b) any stock option plan of the
Company (including the Company's 1996 Stock Option Plan), in the event that a
Change in Control shall occur, all Options held by Executive shall become
immediately exercisable notwithstanding any vesting provision or service
requirement previously applicable to the Option. In the event that a Change in
Control occurs and Executive's employment is terminated by the Company other
than For


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Cause (other than a termination resulting from a Disability) during the two year
period immediately following the date of the Change in Control; or a Change in
Control occurs and Executive terminates Executive's employment with the Company
For Good Reason during the two year period following the date of the Change in
Control, then the Executive shall be entitled under the terms specified to (i)
the payment specified in Section 8(c)(A), except to include Executive's Target
Bonus and except for a period of eighteen (18) months following the date of his
termination payable in a lump sum cash amount within thirty (30) days of the
effective date of termination; and, (ii) health insurance benefits specified in
Section 8(c)(D), except for a period of eighteen (18) months following the date
of his termination. If there is a Change of Control after the Executive's
termination, the amounts, if any, remaining to be paid pursuant to (A) above
shall be paid in a lump sum within ten (10) days thereafter.

          (d) Termination with Cause or Voluntary Resignation or Retirement. If
Executive's employment hereunder is terminated (i) by the Company for Cause,
(ii) voluntarily by the Executive or (iii) by the Company pursuant to Section
7(a)(v) hereof, the Executive shall be entitled to receive only his Base Salary
through the date of termination and any unreimbursed business expenses payable
pursuant to Section 6. Any Executive's rights under any benefit plan of the
Company or any equity plan of the Company following such termination of
employment shall be determined in accordance with the provisions of the
applicable benefit or equity plan.

          (e) Release. Executive agrees that, as a condition to receiving the
payments and benefits provided under Section 8(c) (other than payments provided
under Section 8(c)(B)), he will execute and deliver to the Company a release,
promptly


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following his final day of employment with the Company, of all claims of any
kind against the Company and its affiliates (including, without limitation, any
civil rights claim) and their officers, directors and employees, in such form as
reasonably requested by the Company.

          9. No Mitigation; Set-Off. In the event of any termination of
employment under Section 7, Executive shall be under no obligation to seek other
employment and, subject to Section 11 below, there shall be no offset against
any amounts due Executive under this Agreement on account of any remuneration
attributable to any subsequent employment that Executive may obtain. Any amounts
due under Section 8 are in the nature of severance payments, or liquidated
damages, or both, and are not in the nature of a penalty. Such amounts are
inclusive, and in lieu of any amounts payable under any other salary
continuation or cash severance arrangement of the Company and to the extent paid
or provided under any other such arrangement shall be offset from the amount due
hereunder. The Company shall have no obligations to Executive upon a termination
of employment except as provided in Section 8. If the Executive dies while
receiving payments under Section 8(c), any remaining payments shall be paid to
Executive's estate.

          10. Change in Control. "Change in Control" shall mean (i) the
acquisition by any person, entity or group of persons or entities, other than
the DLJ Entities and their affiliates (including investors in the DLJ Entities)
directly or indirectly, acting in concert of securities representing fifty
percent (50%) or more of the combined voting power of the Company's then
outstanding securities, whether acquired in one transaction or a series of
transactions, (ii) a merger, consolidation or similar transaction


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which results in the Company's shareholders immediately prior to such
transaction not holding securities representing fifty percent (50%) or more of
the total voting power of the outstanding securities of the surviving
corporation or (iii) a sale of all or substantially all of the Company's assets
(other than to an entity owned by the Company or under common ownership with the
Company). Notwithstanding the foregoing, Change in Control shall not be deemed
any change due to a public offering or any transfer of publicly traded
securities.

          11. Confidential Information, Non-Competition and Non-Solicitation of
the Company. (a) (i) Executive acknowledges that as a result of his employment
by the Company, the Executive will obtain secret and confidential information as
to the Company and its affiliates, create relationships with customers,
suppliers and other persons dealing with the Company and its affiliates, and the
Company and its affiliates will suffer substantial damage, which would be
difficult to ascertain, if Executive should use such confidential information or
take advantage of such relationships and that because of the nature of the
information that will be known to Executive and the relationships created it is
necessary for the Company and its affiliates to be protected by the prohibition
against Competition as set forth herein, as well as the Confidentiality
restrictions set forth herein.

               (ii) Executive acknowledges that the (a) retention of nonclerical
employees employed by the Company and its affiliates in which the Company and
its affiliates have invested training and depends on for the operation of their
businesses is important to the businesses of the Company and its affiliates,
that Executive will obtain unique information as to such employees as an
executive of the Company and will


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develop a unique relationship with such persons as a result of being an
executive of the Company and (b) retention of customers by the Company and its
affiliates in which the Company and its affiliates have invested time and
efforts and depends on for the operation of their businesses is important to the
businesses of the Company and its affiliates, that Executive will obtain unique
information as to such customers as an executive of the Company and will develop
a unique relationship with such customers as a result of being an executive of
the Company, therefore, in each case it is necessary for the Company and its
affiliates to be protected from the Executive's Solicitation of such employees
and customers as set forth below.

               (iii) Executive acknowledges that the provisions of this
Agreement are reasonable and necessary for the protection of the businesses of
the Company and its affiliates and that part of the compensation paid under this
Agreement and the agreement to pay severance in certain instances is in
consideration for the agreements in this Section 11.

          (b) Competition shall mean: (i) participating, directly or indirectly,
as an individual proprietor, partners, stockholder, officer, employee, director,
joint venturer, investor, lender, consultant or in any capacity whatsoever,
within the United States of America, in a business in competition with any
business conducted by the Company provided, however, that such participation
shall not include (i) the mere ownership of not more than one percent (1%) of
the total outstanding stock of a publicly held company; or (ii) any activity
engaged in with the prior written approval of the Board.

          (c) Solicitation shall mean: (i) recruiting, soliciting or inducing,
of any nonclerical employee or employees of the Company or its affiliates to
terminate their


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employment with, or otherwise cease their relationship with, the Company or its
affiliates or hiring or assisting another person or entity to hire any
nonclerical employee of the Company or its affiliates or any person who within
six (6) months before had been a nonclerical employee of the Company or its
affiliates and were recruited or solicited for such employment or other
retention while an employee of the Company or affiliate, or (ii) call upon any
Person who or that is, on the Termination Date, or has been, within one year
prior to the Termination Date, a customer of the Company or an affiliate or a
subsidiary for the purpose of (A) soliciting or selling services in competition
with services that the Company or an affiliate or a subsidiary offers or has
under development on the Termination Date, or (B) causing any such customers to
refrain from doing business with or patronizing the Company or an affiliate or a
subsidiary..

          (d) If any restriction set forth with regard to Competition or
Solicitation is found by any court of competent jurisdiction, or an arbitrator,
to be unenforceable because it extends for too long a period of time or over too
great a range of activities or in too broad a geographic area, it shall be
interpreted to extend over the maximum period of time, range of activities or
geographic area as to which it may be enforceable. If any provision of this
Section 11 shall be declared to be invalid or unenforceable, in whole or in
part, as a result of the foregoing, as a result of public policy or for any
other reason, such invalidity shall not affect the remaining provisions of this
Section which shall remain in full force and effect.

          (e) During and after the Employment Term, Executive shall hold in a
fiduciary capacity for the benefit of the Company and its affiliates all secret
or confidential information, knowledge or data relating to the Company and its
affiliates,


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and their respective businesses, including any confidential information as to
customers of the Company and its affiliates, (i) obtained by Executive during
his employment by the Company and its affiliates and (ii) not otherwise public
knowledge or known within the applicable industry (other than by acts by
Executive in violation of this Agreement). The Executive shall not, without
prior written consent of the Company, unless compelled pursuant to the order of
a court or other governmental or legal body having jurisdiction over such
matter, communicate or divulge any such information, knowledge or data to anyone
other than the Company and those designated by it. In the event Executive is
compelled by order of a court or other governmental or legal body to communicate
or divulge any such information, knowledge or data to anyone other than the
Company and those designated by it, he shall promptly notify the Company of any
such order and he shall cooperate fully with the Company in protecting such
information to the extent possible under applicable law.

          (f) Upon termination of his employment with the Company and its
affiliates, or at any time as the Company may request, the Executive will
promptly deliver to the Company all documents (whether prepared by the Company,
an affiliate, the Executive or a third party) relating to the Company, an
affiliate or any of their businesses or property which he may possess or have
under his direction or control.

          (g) During the Employment Term and for one (1) year following a
termination of Executive's employment for any reason whatsoever, whether by the
Company or by Executive and whether or not for Cause or non-extension of the
Employment Term, Executive will not enter into Competition with the Company or
its affiliates. Furthermore, in the event of any termination of Executive's
employment for


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any reason whatsoever, whether by the Company or by the Executive and whether or
not for Cause or non-extension of the Employment Term, the Executive for one (1)
year thereafter will not violate paragraph (c) above.

          (h) In the event of a breach or potential breach or threatened breach
of this Section 11, the Executive acknowledges that the Company and its
affiliates will be caused irreparable injury and that money damages may not be
an adequate remedy and agree that the Company and its affiliates shall be
entitled to injunctive relief (in addition to its other remedies at law) to have
the provisions of this Section 11 enforced. It is hereby acknowledged that the
provisions of this Section 11 are for the benefit of the Company and all of the
affiliates of the Company and each such entity may enforce the provisions of
this Section 11 and only the applicable entity can waive the rights hereunder
with respect to its confidential information and employees.

          (i) Furthermore, in the event of breach of this Section 11 by the
Executive, the Company shall suffer substantial damages that may be difficult to
measure. Accordingly, the parties agree that as liquidated damages, and not a
penalty, in the event of breach of the Section 11 by Executive while he is
receiving amounts under Section 8(c) hereof, Executive shall not be entitled to
receive any future amounts pursuant to Section 8(c) hereof and that this
provision shall not be an exclusive remedy.

          12. Executive's Representation. The Executive represents and warrants
to the Company that there is no legal impediment to his performing his
obligations under this Agreement and neither entering into this Agreement nor
performing his contemplated service hereunder will violate any agreement to
which he is a party or any other legal restriction.


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          13. Miscellaneous.

          (a) Governing Law. This Agreement shall be governed by and construed
in accordance with the laws of the State of New Jersey without reference to
principles of conflict of laws.

          (b) Entire Agreement/Amendments. This Agreement and the instruments
contemplated herein contain the entire understanding of the parties with respect
to the employment of Executive by the Company and supersedes any policy of the
Company with regard to severance payments and any prior agreements between the
Company and Executive with regard to employment or severance. There are no
restrictions, agreements, promises, warranties, covenants or undertakings
between the parties with respect to the subject matter herein other than those
expressly set forth herein and therein. This Agreement may not be altered,
modified, or amended except by written instrument signed by the parties hereto.

          (c) No Waiver. The failure of a party to insist upon strict adherence
to any term of this Agreement on any occasion shall not be considered a waiver
of such party's rights or deprive such party of the right thereafter to insist
upon strict adherence to that term or any other term of this Agreement. Any such
waiver must be in writing and signed by Executive or an authorized officer of
the Company, as the case may be.

          (d) Assignment. This Agreement shall not be assignable by Executive.
This Agreement shall be assignable by the Company only to either an entity which
is owned, directly or indirectly, in whole or in part by the Company or by any
successor to the Company or an acquiror of all or substantially all of the
assets of the Company


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provided such entity or acquiror promptly assumes all of the obligations
hereunder of the Company in a writing delivered to the Executive and otherwise
complies with the provisions hereof with regard to such assumption. Upon such
assignment and assumption, all references to the Company herein shall be to the
assignee entity or acquiror, as the case may be.

          (e) Successors; Binding Agreement. This Agreement shall inure to the
benefit of and be binding upon the personal or legal representatives, executors,
administrators, successors, heirs, distributees, and devisees legatees and
permitted assignees of the parties hereto.

          (f) Communications. For the purpose of this Agreement, notices and all
other communications provided for in this Agreement shall be in writing and
shall be deemed to have been duly given (i) when faxed or delivered by hand,
provided there is documentation of delivery, or (ii) two business days after
being mailed by United States registered or certified mail, return receipt
requested, postage prepaid, addressed to the respective addresses set forth on
the initial page of this Agreement, provided that all notices to the Company
shall be directed to the attention of the Board with a copy to the Vice
President, General Counsel, or to such other address as any party may have
furnished to the other in writing in accordance herewith. Notice of change of
address shall be effective only upon receipt.

          (g) Withholding Taxes. The Company may withhold from any and all
amounts payable under this Agreement such Federal, state and local taxes as may
be required to be withheld pursuant to any applicable law or regulation.


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          (h) Survivorship. The respective rights and obligations of the parties
hereunder shall survive any termination of Executive's employment to the extent
necessary to the agreed preservation of such rights and obligations.

          (i) Counterparts. This Agreement may be signed in counterparts, each
of which shall be an original, with the same effect as if the signatures thereto
and hereto were upon the same instrument.

          (j) Headings. The headings of the sections contained in this Agreement
are for convenience only and shall not be deemed to control or affect the
meaning or construction of any provision of this Agreement.

          IN WITNESS WHEREOF, the parties hereto have duly executed this
Agreement as of the day and year first above written.

For: CommVault Systems, Inc. (the "Company")

/s/ Louis F. Miceli                       2/1/04
-------------------------------------   ----------------------------------------
Louis F. Miceli                         Date
Vice President,
Chief Financial Officer

/s/ N. Robert Hammer                      2/1/04
-------------------------------------   ----------------------------------------
N. Robert Hammer                        Date


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