DATA DOMAIN, INC. 2007 EQUITY INCENTIVE PLAN NOTICE OF STOCK OPTION GRANT

Name of Optionee:

«Name»

Total Number of Shares:

«TotalShares»

Type of Option:

Nonstatutory Stock Option

Exercise Price per Share:

$«PricePerShare»

Date of Grant:

«DateGrant»

Vesting Commencement Date:

«VestDay»

Vesting Schedule:

This option becomes exercisable with respect to the first 25% of the shares subject to this option when you complete 12 months of continuous Service from the Vesting Commencement Date. Thereafter, this option becomes exercisable with respect to an additional 1/48th of the shares subject to this option when you complete each month of Service.

Expiration Date:

«ExpDate». This option expires earlier if your Service terminates earlier, as described in the Stock Option Agreement.

By:                                                                                            

Title:                                                                                         

This option is intended to be a nonstatutory stock option as provided in the Notice of Stock Option Grant.

This option becomes exercisable in installments, as shown in the Notice of Stock Option Grant.

This option may become exercisable on an accelerated basis pursuant to Section 10.3 of the Plan.

This option will in no event become exercisable for additional shares after your Service has terminated for any reason.

This option expires in any event at the close of business at Company headquarters on the day before the 10^th anniversary of the Date of Grant, as shown in the Notice of Stock Option Grant. (It will expire earlier if your Service terminates, as described below.)

If your Service terminates for any reason except death or total and permanent disability, then this option will expire at the close of business at Company headquarters on the date three months after your termination date. The Company determines when your Service terminates for this purpose.

If you die before your Service terminates, then this option will expire at the close of business at Company headquarters on the date 12 months after the date of death.

If your Service terminates because of your total and permanent disability, then this option will expire at the close of business at Company headquarters on the date 12 months after your termination date.

For all purposes under this Agreement, “total and permanent disability” means that you are unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or which has lasted, or can be expected to last, for a continuous period of not less than one year.

Leaves of Absence

and Part-Time

Work

For purposes of this option, your Service does not terminate when you go on a military leave, a sick leave or another bona fide leave of absence, if the leave was approved by the Company in writing. But your Service terminates when the approved leave ends, unless you immediately return to active work.

If you go on a leave of absence, then the vesting schedule specified in the Notice of Stock Option Grant may be adjusted in accordance with the Company’s leave of absence policy or the terms of your leave. If you commence working on a part-time basis, then the vesting schedule specified in the Notice of Stock Option Grant may be adjusted in accordance with the Company’s part-time work policy or the terms of an agreement between you and the Company pertaining to your part-time schedule.

The Company will not permit you to exercise this option if the issuance of shares at that time would violate any law or regulation.

When you wish to exercise this option, you must notify the Company by filing the proper “Notice of Exercise” form at the address given on the form. Your notice must specify how many shares you wish to purchase. Your notice must also specify how your shares should be registered. The notice will be effective when the Company receives it.

If someone else wants to exercise this option after your death, that person must prove to the Company’s satisfaction that he or she is entitled to do so.

When you submit your notice of exercise, you must include payment of the option exercise price for the shares that you are purchasing. To the extent permitted by applicable law, payment may be made in one (or a combination of two or more) of the following forms:

•      Your personal check, a cashier’s check or a money order.

•      Certificates for shares of Company stock that you own, along with any forms needed to effect a transfer of those shares to the Company. The value of the shares, determined as of the effective date of the option exercise, will be applied to the option exercise price. Instead of surrendering shares of Company stock, you may attest to the ownership of those shares on a form provided by the Company and have the same number of shares subtracted from the option shares issued to you.

•      Irrevocable directions to a securities broker approved by the Company to sell all or part of your option shares and to deliver to the Company from the sale proceeds an amount sufficient to pay the option exercise price and any withholding taxes. (The balance of the sale proceeds, if any, will be delivered to you.) The directions must be given by signing a special “Notice of Exercise” form provided by the Company.

Withholding

Taxes and Stock

Withholding

You will not be allowed to exercise this option unless you make arrangements acceptable to the Company to pay any withholding taxes that may be due as a result of the option exercise. With the Company’s consent, these arrangements may include withholding shares of Company stock that otherwise would be issued to you when you exercise this option. The value of these shares, determined as of the effective date of the option exercise, will be applied to the withholding taxes.

Restrictions on

Resale

You agree not to sell any option shares at a time when applicable laws, Company policies or an agreement between the Company and its underwriters prohibit a sale. This restriction will apply as long as your Service continues and for such period of time after the termination of your Service as the Company may specify.

Prior to your death, only you may exercise this option. You cannot transfer or assign this option. For instance, you may not sell this option or use it as security for a loan. If you attempt to do any of these things, this option will immediately become invalid. You may, however, dispose of this option in your will or a beneficiary designation.

Regardless of any marital property settlement agreement, the Company is not obligated to honor a notice of exercise from your former spouse, nor is the Company obligated to recognize your former spouse’s interest in your option in any other way.

Your option or this Agreement does not give you the right to be retained by the Company or a subsidiary of the Company in any capacity. The Company and its subsidiaries reserve the right to terminate your Service at any time, with or without cause.

You, or your estate or heirs, have no rights as a stockholder of the Company until you have exercised this option by giving the required notice to the Company and paying the exercise price. No adjustments are made for dividends or other rights if the applicable record date occurs before you exercise this option, except as described in the Plan.

In the event of a stock split, a stock dividend or a similar change in Company stock, the number of shares covered by this option and the exercise price per share will be adjusted pursuant to the Plan.

This Agreement will be interpreted and enforced under the laws of the State of Delaware (without regard to their choice-of-law provisions).

The Plan and

Other Agreements

The text of the Plan is incorporated in this Agreement by reference. Capitalized terms not otherwise defined herein shall have the meanings set forth in the Plan.

This Agreement and the Plan constitute the entire understanding between you and the Company regarding this option. Any prior agreements, commitments or negotiations concerning this option are superseded. This Agreement may be amended only by another written agreement between the parties.