UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No. )*

                              STORAGENETWORKS, INC.
                              ---------------------
                                (Name of Issuer)

                     Common Shares, $.01 par value per share
                     ---------------------------------------
                         (Title of Class of Securities)

                                    86211E103
                                    ---------
                                 (CUSIP Number)

                               September 11, 2003
                               ------------------
                      (Date of Event which Requires Filing
                               of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

                  [ ] Rule 13d-1(b)
                  [X] Rule 13d-1(c)
                  [ ] Rule 13d-1(d)


*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).

                          Continued on following pages
                               Page 1 of 16 Pages
                              Exhibit List: Page 15





                                  SCHEDULE 13G

CUSIP No.  86211E103                                          Page 2 of 16 Pages



1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  MARVIN H. DAVIDSON

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                     UNITED STATES

                            5             Sole Voting Power
Number of                                          5,048,152
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,048,152
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,048,152

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [ X  ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.07%

12       Type of Reporting Person (See Instructions)

                                    IN; HC



CUSIP No.  86211E103                                          Page 3 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  THOMAS L. KEMPNER, JR.

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                     UNITED STATES

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439
10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC




CUSIP No.  86211E103                                          Page 4 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  STEPHEN M. DOWICZ

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                      UNITED STATES

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC



CUSIP No.  86211E103                                          Page 5 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  SCOTT E. DAVIDSON

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                      UNITED STATES

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC



CUSIP No.  86211E103                                          Page 6 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  MICHAEL J. LEFELL

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                      UNITED STATES

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC



CUSIP No.  86211E103                                          Page 7 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  TIMOTHY I. LEVART

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                      UNITED KINGDOM

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC



CUSIP No.  86211E103                                          Page 8 of 16 Pages

1        Names of Reporting Persons
         I.R.S. Identification Nos. of above persons (entities only)

                  ROBERT J. BRIVIO, JR.

2        Check the Appropriate Box If a Member of a Group (See Instructions)

                                                      a. [ ]
                                                      b. [X]

3        SEC Use Only

4        Citizenship or Place of Organization

                      UNITED STATES

                            5             Sole Voting Power
Number of                                          5,062,439
  Shares
Beneficially                6             Shared Voting Power
  Owned By                                         0
    Each
Reporting                   7             Sole Dispositive Power
    Person                                         5,062,439
    With
                            8             Shared Dispositive Power
                                                   0

9        Aggregate Amount Beneficially Owned by Each Reporting Person

                                    5,062,439

10       Check Box If the Aggregate Amount in Row (9) Excludes Certain
         Shares (See Instructions)

                                    [   ]

11       Percent of Class Represented By Amount in Row (9)

                                    5.09%

12       Type of Reporting Person (See Instructions)

                                    IN; HC







                                                             Page 9 of 16 Pages

Item 1(a)         Name of Issuer:

                  StorageNetworks, Inc. (the "Issuer")

Item 1(b)         Address of the Issuer's Principal Executive Offices:

                  275 Grove Street, Newton, Massachusetts 02466

Item 2(a)         Name of Person Filing:

                  The Statement is filed on behalf of each of the following
persons (collectively, the "Reporting Persons"):

                  i) Marvin H. Davidson ("Mr. Marvin Davidson");

                  ii) Thomas L. Kempner, Jr. ("Mr. Kempner");

                  iii) Stephen M. Dowicz ("Mr. Dowicz");

                  iv) Scott E. Davidson ("Mr. Scott Davidson");

                  v) Michael J. Leffell ("Mr. Lefell");

                  vi) Timothy I. Levart ("Mr. Levart); and

                  vii) Robert J. Brivio, Jr. ("Mr. Brivio").

     This statement  relates to shares (as defined herein) held for the accounts
of (i) M.H. Davidson & Co., a New York corporation ("CO"), (ii) Davidson Kempner
International,  Ltd.,  a British  Virgin  Islands  corporation  ("DKIL"),  (iii)
Davidson Kempner  Institutional  Partners,  L.P., a Delaware limited partnership
("DKIP"),  (iii)  Davidson  Kempner  Partners,  a New York  limited  partnership
("DKP"),  (iv)  Davidson  Kempner  International  Advisors,  L.L.C.,  a Delaware
limited liability company ("DKIA"),  and (v) M.H. Davidson & Co., L.L.C.  401(K)
Plan (the "Plan").  The Reporting Persons are the general partners of CO and the
sole stockholders of Davidson Kempner Advisers Inc., a New York corporation, the
general partner of DKIP. The Reporting  Persons are also the general partners of
MHD Management Co., a New York corporation, the general partner of DKP. Finally,
the Reporting Persons are the sole stockholders of DKIA, the manager of DKIL. In
such capacity,  DKIA may be deemed to have voting and dispositive power over the
Shares  held for the  account of DKIL.  As a result of the above  relationships,
each of the Reporting Persons may be deemed to have voting and dispositive power
over the Shares held for the accounts of CO, DKIL,  DKIP, DKP and DKIA.  Each of
the  Reporting  Persons,  with the exception of Mr.  Marvin  Davidson,  serve as
trustees  of the Plan.  As a result,  each of the  Reporting  Persons,  with the
exception  of Mr.  Marvin  Davidson,  may  also be  deemed  to have  voting  and
dispositive power over the Shares held for the account of the Plan.

Item 2(b)         Address of Principal Business Office or, if None, Residence:

                  The address of the  principal  business  office of each of the
Reporting Persons is 885 Third Avenue, New York, NY 10022.




                                                             Page 10 of 16 Pages

Item 2(c)         Citizenship:

                  1) Mr. Marvin Davidson is a citizen of the United States;

                  2) Mr. Kempner is a citizen of the United States;

                  3) Mr. Dowicz is a citizen of the United States;

                  4) Mr. Scott Davidson is a citizen of the United States;

                  5) Mr. Lefell is a citizen of the United States;

                  6) Mr. Levart is a citizen of the United Kingdom; and

                  7) Mr. Brivio is a citizen of the United States.

Item 2(d)         Title of Class of Securities:

                  Common shares, no par value (the "Shares").

Item 2(e)         CUSIP Number:

                  86211E103

Item 3.           If this  statement  is filed  pursuant  to Rule  13d-1(b),  or
                  13d-2(b) or (c), check whether the person filing is a:

                  This Item 3 is not applicable.

Item 4.           Ownership:

Item 4(a)         Amount Beneficially Owned:

                  (1)  As of September  11,  2003,  Mr.  Marvin  Davidson may be
deemed the  beneficial  owner of 5,048,152  Shares.  Of this amount,  (i) 75,722
Shares are held for the  account of CO, (ii)  2,178,229  Shares are held for the
account of DKIL,  (iii)  90,868  Shares are held for the  account of DKIA,  (iv)
1,753,468  Shares are held for the account of DKIP,  and (iv) 949,865 Shares are
held for the account of DKP.

                  (2)  As of  September  11,  2003,  each  of Mr.  Kempner,  Mr.
Dowicz, Mr. Scott Davidson, Mr. Leffell, Mr. Levart and Mr. Brivio may be deemed
the beneficial owner of 5,062,439 Shares. Of this amount,  (i) 75,722 Shares are
held for the  account of CO, (ii)  2,178,229  Shares are held for the account of
DKIL,  (iii)  90,868  Shares are held for the  account of DKIA,  (iv)  1,753,468
Shares are held for the  account of DKIP,  (v)  949,865  Shares are held for the
account of DKP, and (v) 14,287 Shares are held for the account of the Plan.

Item 4(b)         Percent of Class:

                  (1)  The number of Shares of which Mr. Marvin  Davidson may be
deemed to be the  beneficial  owner  constitutes  5.07% of the  total  number of
Shares  outstanding  (based upon information  provided by the Issuer in its most


                                                             Page 11 of 16 Pages

recent proxy  statement on Schedule  14A, the number of Shares  outstanding  was
99,538,552 as of September 4, 2003).

                  (2)  The  number of Shares of which each of Mr.  Kempner,  Mr.
Dowicz, Mr. Scott Davidson, Mr. Leffell, Mr. Levart and Mr. Brivio may be deemed
to be the  beneficial  owner  constitutes  5.09% of the  total  number of Shares
outstanding  (based upon  information  provided by the Issuer in its most recent
proxy statement on Schedule 14A, the number of Shares outstanding was 99,538,552
as of September 4, 2003).




Item 4(c)         Number of shares as to which such person has:
                                                                      

Mr. Marvin Davidson
(i)       Sole power to vote or direct the vote:                       5,048,152
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,048,152
(iv)      Shared power to dispose or to direct the disposition of              0

Mr. Kempner
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0

Mr. Dowicz
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0

Mr. Scott Davidson
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0

Mr. Leffell
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0





                                                             Page 12 of 16 Pages

Mr. Levart
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0

Mr. Brivio
(i)       Sole power to vote or direct the vote:                       5,062,439
(ii)      Shared power to vote or to direct the vote                           0
(iii)     Sole power to dispose or to direct the disposition of        5,062,439
(iv)      Shared power to dispose or to direct the disposition of              0


Item 5.           Ownership of Five Percent or Less of a Class:

                  This Item 5 is not applicable.

Item 6.           Ownership  of More than  Five  Percent  on  Behalf of  Another
                  Person:

                  (i)    The shareholders of CO have the right to participate in
the receipt of dividends  from, or proceeds from the sale of, the Shares held by
CO in accordance with their ownership interests in CO.

                  (ii)   The  shareholders of DKIL have the right to participate
in the receipt of dividends  from, or proceeds from the sale of, the Shares held
by CO in accordance with their ownership interests in DKIL.

                  (iii)  The partners of DKIP have the right to  participate  in
the receipt of dividends  from, or proceeds from the sale of, the Shares held by
DKIP in accordance with their partnership interests in DKIP.

                  (iv)   The  partners of DKP have the right to  participate  in
the receipt of dividends  from, or proceeds from the sale of, the Shares held by
DKP in accordance with their partnership interests in DKP.

                  (v)    The   participants  in  the  Plan  have  the  right  to
participate in the receipt of dividends  from, or proceeds from the sale of, the
Shares held by the Plan in accordance with their interests in the Plan.

Item 7.           Identification  and  Classification  of the  Subsidiary  Which
                  Acquired the Security  Being Reported on by the Parent Holding
                  Company or Control Person:

                  This Item 7 is not applicable.

Item 8.           Identification and Classification of Members of the Group:

                  This Item 8 is not applicable.


                                                             Page 13 of 16 Pages

Item 9.           Notice of Dissolution of Group:

                  This Item 9 is not applicable.

Item 10.          Certification:

                  By signing below each of the Reporting Persons certifies that,
to the best of such person's  knowledge and belief,  the securities  referred to
above were acquired and are held in the ordinary course of business and were not
acquired  and are not held for the  purpose of or with the effect of changing or
influencing  the control of the Issuer of such  securities and were not acquired
and are not  held in  connection  with or as a  participant  in any  transaction
having such purpose or effect.





                                                             Page 14 of 16 Pages



                                   SIGNATURES


     After  reasonable  inquiry and to the best of my knowledge and belief,  the
undersigned  certifies that the information set forth in this statement is true,
complete and correct.


Date:    September 18, 2003                           MARVIN H. DAVIDSON


                                                      /s/ Marvin H. Davidson
                                                      --------------------------

Date:    September 18, 2003                           THOMAS L. KEMPNER, JR.


                                                      /s/ Thomas L. Kempner, Jr.
                                                      --------------------------

Date:    September 18, 2003                           STEPHEN M. DOWICZ


                                                      /s/ Stephen M. Dowicz
                                                      --------------------------

Date:    September 18, 2003                           SCOTT E. DAVIDSON


                                                      /s/ Scott E. Davidson
                                                      --------------------------

Date:    September 18, 2003                           MICHAEL J. LEFFELL


                                                      /s/ Michael J. Leffell
                                                      --------------------------

Date:    September 18, 2003                           TIMOTHY I. LEVART


                                                      /s/ Timothy I. Levart
                                                      --------------------------

Date:    September 18, 2003                           ROBERT J. BRIVIO, JR.


                                                      /s/ Robert J. Brivio, Jr.
                                                      --------------------------





                                                             Page 15 of 16 Pages




                                  EXHIBIT INDEX

                                                                        Page No.
                                                                        --------

A.  Joint  Filing  Agreement dated as of September  18, 2003, by and
    among Mr. Marvin H. Davidson, Mr. Thomas L. Kempner, Jr., Mr. Stephen M.
    Dowicz, Mr. Scott E. Davidson, Mr. Michael J. Leffell, Mr. Timothy I.
    Levart, and Mr. Robert J. Brivio, Jr.................................. 16