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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Carlyle Realty IV GP, L.L.C.
 2. Date of Event Requiring Statement (Month/Day/Year)
07/31/2011		 3. Issuer Name and Ticker or Trading Symbol
CoreSite Realty Corp [COR]
(Last)
(First)
(Middle)
1001 PENNSYLVANIA AVE NW, SUITE 220 SOUTH		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

WASHINGTON, DC 20004		 6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ 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)
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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
operating partnership units   (1)   (1) Common Stock 25,275,390 $ (1) I See footnotes (2) (3) (4) (5)

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Carlyle Realty IV GP, L.L.C.
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
Carlyle Realty IV, L.P.
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
CoreSite CRP IV Holdings, LLC
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
CRP IV AIV GP, L.L.C.
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
CRP IV AIV GP, L.P.
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
CRQP IV AIV, L.P.
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    
CoreSite CRP IV Holdings (VCOC I), LLC
1001 PENNSYLVANIA AVE NW
SUITE 220 SOUTH
WASHINGTON, DC 20004		     X    

Signatures

/s/ R. Rainey Hoffman, attorney-in-fact 08/02/2011
**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) Beginning September 29, 2011, the OP Units will be redeemable for cash or, at the option of the Company, exchangeable into shares of Common Stock on a one-for-one basis.
(2) CoreSite CRP III Holdings, LLC, CoreSite CRP III Holdings (VCOC), LLC, CoreSite CRP IV Holdings, LLC, CoreSite CRP IV Holdings (VCOC I), LLC, CoreSite CRP IV Holdings (VCOC II), LLC and CoreSite CRP V Holdings, LLC (together, the "Limited Partners") are the record holders of 6,222,640, 1,260,550, 4,360,826, 742,637, 1,908,756 and 10,779,980 limited partnership units of CoreSite, L.P., respectively (collectively, the "OP Units"). DBD Investors V Holdings, L.L.C. exercises investment discretion and control over the OP Units through its indirect subsidiary, TC Group Investment Holdings, L.P., which is the managing member of each of Carlyle Realty III GP, L.L.C., CRP III AIV GP, L.L.C., Carlyle Realty IV GP, L.L.C., CRP IV AIV GP, L.L.C. and Carlyle Realty V GP, L.L.C. (Continued in footnote 3)
(3) Carlyle Realty III GP, L.L.C. is the general partner of Carlyle Realty III, L.P. which is the managing member of CoreSite CRP III Holdings, LLC. CRP III AIV GP, L.L.C. is the general partner of CRP III AIV GP, L.P., which is the general partner of CRQP III AIV, L.P., which is the managing member of CoreSite CRP III Holdings (VCOC), LLC. Carlyle Realty IV GP, L.L.C. is the general partner of Carlyle Realty IV, L.P., which is the managing member of CoreSite CRP IV Holdings, LLC. CRP IV AIV GP, L.L.C. is the general partner of CRP IV AIV GP, L.P., which is the general partner of each of CRP IV-A AIV, L.P. and CRQP IV AIV, L.P., which are the managing members of CoreSite CRP IV Holdings (VCOC I), LLC and CoreSite CRP IV Holdings (VCOC II), LLC, respectively. Carlyle Realty V GP, L.L.C. is the general partner of Carlyle Realty V, L.P., which is the managing member if CoreSite CRP V Holdings, LLC. (Continued in footnote 4)
(4) DBD Investors V Holdings, L.L.C. is the managing member of DBD Investors V, L.L.C. DBD Investors V, L.L.C. is the general partner of TCG Holdings II, L.P. TCG Holdings II, L.P. is the general partner of TC Group Investment Holdings, L.P. Each of the reporting persons expressly disclaims beneficial ownership of any such securities, except to the extent of its pecuniary interest therein. DBD Investors V Holdings, L.L.C. is managed by a three person managing board, and all board action relating to the voting or disposition of the OP Units requires approval of a majority of the board. William E. Conway, Jr., Daniel A. D'Aniello and David M. Rubenstein, as the members of the DBD Investors V Holdings, L.L.C. managing board, may be deemed to share beneficial ownership of the OP Units beneficially owned by DBD Investors V Holdings, L.L.C. Such persons disclaim such beneficial ownership.
(5) Due to the limitations of the electronic filing system, DBD Investors V Holdings, L.L.C., TCG Holdings II, L.P., TC Group Investment Holdings, L.P., Carlyle Realty III, GP, L.L.C., Carlyle Realty III, L.P., CoreSite CRP III Holdings, LLC, Carlyle Realty V GP, L.L.C., Carlyle Realty V, L.P. and CoreSite CRP V Holdings, LLC are filing a separate Form 3. DBD Investors V, L.L.C. filed a separate Form 3 on September 28, 2010.
 
Remarks:
Exhibit List

Exhibit 24 - Confirming Statement
Exhibit 99.1 - Joint Filer Information

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