X0202 3 2006-12-14 0 0001373671 Isilon Systems, Inc. ISLN 0001378834 Schrandt Mark L C/O ISILON SYSTEMS, INC. 3101 WESTERN AVENUE SEATTLE WA 98121 0 1 0 0 VP Engineering Common Stock 551416 D Employee Stock Option (Right to Buy) 0.22 2014-04-29 Common Stock 166666 D Employee Stock Option (Right to Buy) 0.22 2015-03-10 Common Stock 33333 D Employee Stock Option (Right to Buy) 0.82 2016-02-13 Common Stock 20833 D Employee Stock Option (Right to Buy) 0.82 2016-03-30 Common Stock 66666 D The shares of common stock are subject to a right of repurchase in favor of the Issuer upon Mr. Schrandt's cessation of service, which right of repurchase terminates on November 4, 2007. The option is exercisable at the rate of 1/4th of the shares on April 29, 2005 and 1/36th of the remaining shares on each monthly anniversary thereafter. The option is exercisable at the rate of 1/4th of the shares on March 10, 2006 and 1/36th of the remaining shares on each monthly anniversary thereafter. The option is exercisable at the rate of 1/4th of the shares on January 1, 2007 and 1/36th of the remaining shares on each monthly anniversary thereafter. The option is exercisable at the rate of 1/4th of the shares on March 10, 2007 and 1/36th of the remaining shares on each monthly anniversary thereafter. /s/ Douglas Choi, attorney-in-fact 2006-12-13