UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C.  20549

SCHEDULE 13D

(RULE 13D - 101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO § 240.13d-2(a)

(Amendment No. 6)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

ERIC SINGER

VIEX CAPITAL ADVISORS, LLC

825 Third Avenue, 33rd Floor

New York, New York 10022

 

CHRISTOPHER P. DAVIS, ESQ.

KLEINBERG, KAPLAN, WOLFF & COHEN, P.C.

551 Fifth Avenue, New York, New York 10176

(Name, Address and Telephone Number of Person

Authorized to Receive Notices and Communications)

 

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box ¨.

Note: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See § 240.13d-7 for other parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. 747906 20 4

* This Series One is part of a series of VIEX Opportunities Fund, LP, a Delaware series limited partnership.

CUSIP No. 747906 20 4

* This Series Two is part of a series of VIEX Opportunities Fund, LP, a Delaware series limited partnership.

CUSIP No. 747906 20 4

CUSIP No. 747906 20 4

CUSIP No. 747906 20 4

CUSIP No. 747906 20 4

CUSIP No. 747906 20 4

The following constitutes Amendment No. 6 to the Schedule 13D filed by the undersigned (the "Amendment No. 6"). This Amendment No. 6 amends the Schedule 13D as specifically set forth herein.

Item 4.

Purpose of Transaction.

Item 4 is hereby amended to add the following:

On September 23, 2016, the Issuer entered into an agreement (the "Agreement") with the Reporting Persons. Under the Agreement, the Issuer has granted Board observer rights to John Mutch and Raghavendra Rau until December 1, 2016, subject to certain conditions. In addition, the Issuer will use its reasonable best efforts to hold its Annual Meeting of Stockholders on January 31, 2017, or another date mutually agreed by the parties.

Under the Agreement, the Reporting Persons have agreed to abide by certain standstill provisions related to the solicitation of proxies and other matters until December 1, 2016, subject to earlier termination under certain circumstances. The foregoing description of the Agreement is qualified in its entirety by reference to the Agreement, which is attached as Exhibit 99.1 hereto and incorporated herein by reference.

Item 5.

Interest in Securities of the Issuer.

	(a)		As of the date hereof, Series One beneficially owned 7,407,865 Shares.
			Percentage: Approximately 2.8%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 7,407,865
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 7,407,865
	(c)		Series One has not entered into any transactions during the past 60 days.

	(a)		As of the date hereof, Series Two beneficially owned 1,413,191 Shares.
			Percentage: Less than 1%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 1,413,191
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 1,413,191
	(c)		Series Two has not entered into any transactions during the past 60 days.

	(a)		As of the date hereof, VSO III beneficially owned 20,710,666 Shares.
			Percentage: Approximately 7.7%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 20,710,666
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 20,710,666
	(c)		VSO III has not entered into any transactions in the Shares during the past 60 days.

	(a)		VIEX GP, as the general partner of Series One and Series Two, may be deemed the beneficial owner of the (i) 7,407,865 shares owned by Series One and (ii) 1,413,191 shares owned by Series Two.
			Percentage: Approximately 3.3%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 8,821,056
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 8,821,056
	(c)		VIEX GP has not entered into any transactions in the Shares during the past 60 days.

	(a)		VSO GP III, as the general partner of VSO III, may be deemed the beneficial owner of the 20,710,666 shares owned by VSO III.
			Percentage: Approximately 7.7%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 20,710,666
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 20,710,666
	(c)		VSO GP III has not entered into any transactions in the Shares during the past 60 days.

	(a)		VIEX Capital, as the investment manager of Series One and Series Two, may be deemed the beneficial owner of the (i) 7,407,865 Shares owned by Series One, (ii) 1,413,191 Shares owned by Series Two and (iii) 20,710,666 owned by VSO III.
			Percentage: Approximately 11.0%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 29,531,722
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 29,531,722
	(c)		VIEX Capital has not entered into any transactions in the Shares during the past 60 days.

	(a)		Mr. Singer, as the managing member of VIEX GP and VIEX Capital, may be deemed the beneficial owner of the (i) 7,407,865 Shares owned by Series One, (ii) 1,413,191 Shares owned by Series Two and (iii) 20,710,666 owned by VSO III.
			Percentage: Approximately 11.0%
	(b)	1.	Sole power to vote or direct vote: 0
		2.	Shared power to vote or direct vote: 29,531,722
		3.	Sole power to dispose or direct the disposition: 0
		4.	Shared power to dispose or direct the disposition: 29,531,722
	(c)		Mr. Singer has not entered into any transactions in the Shares during the past 60 days.

Item 6.

Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

Item 6 is hereby amended to add the following:

On September 23, 2016, the Reporting Persons and the Issuer entered into the Agreement defined and described in Item 4 above and attached as Exhibit 99.1 hereto.

Item 7.

Material to be Filed as Exhibits.

Item 7 is hereby amended to add the following Exhibit:

Exhibit 99.1 -

Agreement, made and entered into as of September 23, 2016, by and among Quantum Corporation and the entities and natural persons listed on Exhibit A thereto (incorporated by reference to Exhibit 10.1 to the Issuer's Current Report on Form 8-K filed September 26, 2016) (File No. 001-13449).

SIGNATURES

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information with respect to it set forth in this statement is true, complete, and correct.

Dated:

September 27, 2016