X0303 4 2010-04-26 false 0001373671 Isilon Systems, Inc. ISLN 0001439716 Godwin Mary E. 3101 WESTERN AVENUE SEATTLE WA 98121 false true false false VP Operations Common Stock 2010-04-26 4 M false 40000 4.9 A 46600 D Common Stock 2010-04-26 4 S false 40000 13.7893 D 6600 D Stock Option (Right to Buy) 4.9 2010-04-26 4 M false 40000 0 D 2018-08-05 Common Stock 40000 185000 D The option is exercisable at the rate of 25% of the shares on July 9, 2009 and 1/12th of the remaining shares on each quarterly anniversary thereafter, such that the option will be fully exercisable on July 9, 2012. The "Amount" and "Price" reported in this Column 4 reflect the aggregate number and weighted-average price, respectively, of shares disposed. These shares were sold in multiple transactions at prices ranging from $13.716 to $13.82, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the SEC staff, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth herein. Keenan M. Conder, Attorney-in-Fact 2010-04-27