Stock Trading History of Greylock Xi Gp Limited Partnership

The following table details the trading activities (stock purchases, stock sales, and stock option exercises) reported to the Securities and Exchange Commission (SEC) by insider Greylock Xi Gp Limited Partnership since year 2005. The trader's CIK number is 1351699. At the time of this reporting, Greylock Xi Gp Limited Partnership is the 10% Owner of Data Domain, Inc. . (stock ticker symbol DDUP). See this page for all insider trading activities at Data Domain, Inc. .

Stock purchases, sales, and option exercises reported by insider *Greylock Xi Gp Limited Partnership* since 2005.
Trade Date	Symbol	Company Name (Issuer)	Trade Type	Shares	Price ($)	Value ($)
2008-02-28	DDUP	Data Domain, Inc.	Sale	900,000	20.00	18,000,000
2007-12-03	DDUP	Data Domain, Inc.	Sale	85,962	25.89	2,225,556
2007-11-21	DDUP	Data Domain, Inc.	Sale	914,423	25.89	23,671,028

Insider trading activities including stock purchases, stock sales, and option exercises listed in the above table cannot be completely guaranteed as to their accuracy. For more information regarding the trades made by Greylock Xi Gp Limited Partnership (10% Owner of Data Domain, Inc. at the time of this reporting) see the Securities and Exchange Commission (SEC) website.