X0202 4/A 2005-10-27 2005-10-31 0 0001297996 Digital Realty Trust, Inc. DLR 0001191698 MAGNUSON RICHARD A 560 MISSION STREET, SUITE 2900 SAN FRANCISCO CA 94105 1 1 0 0 Executive Chairman Class C Profits Interest Units 2005-10-27 4 A 0 333333 0 A Common Stock 333333 333333 D Class C profit interest units ("Class C Units") are membership interests in Digital Realty Trust, L.P., a Maryland limited partnership of which the issuer is the general partner (the "Operating Partnership"). Sixty percent of the Class C Units will vest on September 30, 2008 and thereafter 1-2/3% will vest monthly, except that 100% of the Class C Units will vest upon a change in control of the issuer, provided in each case that the cumulative return to the issuer's common stockholders as measured from October 1, 2005 exceeds certain targets. (Continued on Footnote 2.) Upon vesting, Class C Units receive the same quarterly distributions as common limited partnership units of the Operating Partnership ("Common Units") but initially may not have full parity with Common Units with respect to liquidating distributions; however, upon the occurrence of specified events, Class C Units may achieve full parity with Common Units for all purposes, and thereafter may be converted into an equal number of Common Units on a one-for-one basis at any time. Common Units will be redeemable for cash based on the fair market value of an equivalent number of shares of the issuer's common stock, or, at the election of the issuer, for an equal number of shares of the issuer's common stock. /s/ A. William Stein, Attorney-in-fact 2005-11-01