Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0104
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
  CAROLAN BRIAN
 2. Date of Event Requiring Statement (Month/Day/Year)
09/21/2006		 3. Issuer Name and Ticker or Trading Symbol
COMMVAULT SYSTEMS INC [CVLT]
(Last)
(First)
(Middle)
2 CRESCENT PLACE		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Accounting Officer
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

OCEANPORT, NJ 07757		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Option (Right to Buy)   (1) 02/05/2011 Common Stock 25,000 $ 8 D  
Stock Option (Right to Buy)   (2) 01/30/2013 Common Stock 15,000 $ 4 D  
Stock Option (Right to Buy)   (2) 11/07/2013 Common Stock 12,500 $ 5 D  
Stock Option (Right to Buy)   (2) 01/29/2014 Common Stock 10,000 $ 7.2 D  
Stock Option (Right to Buy)   (2) 01/27/2015 Common Stock 12,500 $ 5.3 D  
Stock Option (Right to Buy)   (2) 11/17/2015 Common Stock 25,000 $ 6.7 D  
Stock Option (Right to Buy)   (2) 07/27/2016 Common Stock 20,000 $ 12.74 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
CAROLAN BRIAN
2 CRESCENT PLACE
OCEANPORT, NJ 07757		       Chief Accounting Officer  

Signatures

/s/ Brian Carolan 09/21/2006
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The options to purchase 25,000 shares have vested.
(2) The stock options vest as follows: 25% of the options vest one year from the date of grant, with the remaining options vesting in equal quarterly installments for three years thereafter.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.