---

---

UNITED
STATES SECURITIES AND EXCHANGE
COMMISSION Washington, D.C.
20549 FORM
10-K Amendment No. 1


|x |  | ANNUAL REPORT PURSUANT
      TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
1934           |  | 
|- |  | ---------------------------------------------------------------------------------------------------- |  | 
|  |  | For the fiscal year ended March 31,
      2012                                                       |  | 
|  |  | OR                                                                                                   |  | 
| ̈ |  | TRANSITION REPORT
      PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF
      1934 |  | 

|For the transition period from _____
      to _____
|---------------------------------------------------
|Commission file number
    1-13449                 

QUANTUM
CORPORATION(Exact name of registrant
as specified in its charter)

Delaware
    94-2665054(State or other
      jurisdiction of incorporation or organization)
    (I.R.S. Employer
      Identification No.)1650 Technology Drive,
      Suite 800, San Jose, California
    95110(Address of principal
      executive offices)
    (Zip
  Code)


Registrants telephone number,
including area code: (408) 944-4000Securities registered pursuant to Section 12(b) of the Act:

|Title of each class                    |  | Name of each exchange on which
      registered
|-------------------------------------- |  | -----------------------------------------------
|QUANTUM CORPORATION
      COMMON STOCK |  | NEW YORK STOCK EXCHANGE                        

Securities registered pursuant to Section 12(g) of the
Act: NONE


Indicate by check mark whether the
registrant is a well-known seasoned issuer, as defined in Rule 405 of the
Securities Act.     YES   ̈NO  x

Indicate by check mark if the registrant is not
required to file reports pursuant to Section 13 or 15(d) of the
Act.     YES   ̈NO 
x

Indicate by check mark
whether the registrant (1) has filed all reports required to be filed by Section
13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12
months (or for such shorter period that the Registrant was required to file such
reports), and (2) has been subject to such filing requirements for the past 90
days.     YES  xNO 
 ̈

Indicate by checkmark
whether the registrant has submitted electronically and posted on its corporate
website, if any, every Interactive Data File required to be submitted and posted
pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the
preceding 12 months (or for such shorter period that the registrant was required
to submit and post such files).    YES  xNO   ̈

Indicate by check mark if disclosure of delinquent
filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not
contained herein, and will not be contained, to the best of registrants
knowledge, in definitive proxy or information statements incorporated by
reference in Part III of this Form 10-K or any amendment to this Form
10-K.  x

Indicate by checkmark whether the registrant is a
large accelerated filer, an accelerated filer, a non-accelerated filer, or a
smaller reporting company. See the definitions of large accelerated filer,
accelerated filer and smaller reporting company in Rule 12b-2 of the
Exchange Act.

|Large accelerated
      filer      ̈ | Accelerated filer    
      x | Non-accelerated
      filer      ̈ | Smaller Reporting
      Company      ̈
|----------------------------------- | ----------------------------- | --------------------------------- | -------------------------------------

Indicate by check mark whether the registrant is a
shell company (as defined in Rule 12b-2 of the Exchange
Act).     YES   ̈NO 
x

The aggregate market value of Quantum Corporations
common stock, $0.01 par value per share, held by nonaffiliates of the registrant
was approximately $248.4 million on September 30, 2011 the last day of the
registrants most recently completed second fiscal quarter, based on the closing
sales price of the registrants common stock on that date on the New York Stock
Exchange. For purposes of this disclosure, shares of common stock held by
persons who hold more than 5% of the outstanding shares of common stock and
shares held by officers and directors of the registrant have been excluded in
that such persons may be deemed to be affiliates. This determination of
affiliate status is not necessarily conclusive for other purposes.

As of the close of business on June 8, 2012, there
were approximately 236.7 million shares of the registrants common stock issued
and outstanding.

DOCUMENTS INCORPORATED BY
REFERENCE


The registrants definitive Proxy
Statement for the Annual Meeting of Stockholders to be held on August 15, 2012,
which the registrant will file with the Securities and Exchange Commission
within 120 days after the end of the fiscal year covered by this report, is
incorporated by reference in Part III of this Form 10-K to the extent stated
herein.


---

---

---



EXPLANATORY NOTE

The purpose of this Amendment to the Form
10-K for the year ended March 31, 2012, originally filed with the Securities and
Exchange Commission on June 14, 2012 (the "Form 10-K"), is solely to correct the
Report of Independent Registered Public Accounting Firm to include reference to
the Statements of Comprehensive Income (Loss), which was inadvertently omitted
from the initial filing. This Amendment also contains currently dated
certifications as Exhibits 31.1., 31.2, 32.1 and 32.2 and a currently dated
consent of PricewaterhouseCoopers LLP as Exhibit 23. Although only the revised
Report of Independent Registered Public Accounting Firm changed, the entire Item
8 is included in this Amendment.

No other changes have been made to the
Form 10-K. This Amendment speaks as of the original filing date of the Form
10-K, does not reflect events that may have occurred subsequent to the original
filing date and does not modify or update in any way disclosures made in the
original Form 10-K.

1

---



PART II

ITEM 8. FINANCIAL STATEMENTS AND
SUPPLEMENTARY DATA

INDEX TO CONSOLIDATED FINANCIAL
STATEMENTS

|                                                                                                                     | Page | 
|-------------------------------------------------------------------------------------------------------------------- | ---- | 
|Quantum Corporation  Financial
      Statements                                                                     |      | 
|Report
      of PricewaterhouseCoopers LLP, Independent Registered Public Accounting
      Firm                      | 3    | 
|Consolidated Balance
      Sheets as of March 31, 2012 and 2011                                                      | 4    | 
|Consolidated Statements of Operations for the years ended March 31, 2012,
      2011 and 2010                        | 5    | 
|Consolidated Statements
      of Comprehensive Income (Loss) for the years ended March 31, 2012, 2011
      and 2010 | 6    | 
|Consolidated Statements of Cash Flows for the years ended March 31, 2012,
      2011 and 2010                        | 7    | 
|Consolidated Statements
      of Stockholders Deficit for the years ended March 31, 2012, 2011 and
      2010       | 8    | 
|Notes
      to Consolidated Financial Statements                                                                     | 9    | 
|Schedule II 
      Consolidated Valuation and Qualifying Accounts                                                   | 33   | 

2

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Report of Independent Registered Public
Accounting Firm

To the Board of Directors
andStockholders of Quantum Corporation:

In our opinion, the accompanying
consolidated balance sheets and the related consolidated statements of
operations, of comprehensive income (loss), of stockholders' deficit, and of
cash flows present fairly, in all material respects, the financial position of
Quantum Corporation and its subsidiariesat March 31, 2012 and March 31, 2011, and the
results of their operations and their cash flows for each of the three years in
the period ended March 31, 2012in conformity with accounting principles
generally accepted in the United States of America. In addition, in our opinion,
the financial statement schedule listed in the accompanying index appearing
under Item 15(a)(2) presents fairly, in all material respects, the information
set forth therein when read in conjunction with the related
consolidatedfinancial statements. Also in our opinion, the Company maintained, in all
material respects, effective internal control over financial reporting as of
March 31, 2012, based on criteria established inInternal Control - Integrated Frameworkissued by the Committee of Sponsoring Organizations of the Treadway
Commission (COSO). The Company's management is responsible for these financial
statements and financial statement schedule, for maintaining effective internal
control over financial reporting and for its assessment of the effectiveness of
internal control over financial reporting, included in Management's Report on
Internal Control over Financial Reporting appearing under Item 9A. Our
responsibility is to express opinions on these financial statements, on the
financial statement schedule, and on the Company's internal control over
financial reporting based on our integrated audits. We conducted our audits in
accordance with the standards of the Public Company Accounting Oversight Board
(United States). Those standards require that we plan and perform the audits to
obtain reasonable assurance about whether the financial statements are free of
material misstatement and whether effective internal control over financial
reporting was maintained in all material respects. Our audits of the financial
statements included examining, on a test basis, evidence supporting the amounts
and disclosures in the financial statements, assessing the accounting principles
used and significant estimates made by management, and evaluating the overall
financial statement presentation. Our audit of internal control over financial
reporting included obtaining an understanding of internal control over financial
reporting, assessing the risk that a material weakness exists, and testing and
evaluating the design and operating effectiveness of internal control based on
the assessed risk. Our audits also included performing such other procedures as
we considered necessary in the circumstances. We believe that our audits provide
a reasonable basis for our opinions.

A companys internal control over
financial reporting is a process designed to provide reasonable assurance
regarding the reliability of financial reporting and the preparation of
financial statements for external purposes in accordance with generally accepted
accounting principles. A companys internal control over financial reporting
includes those policies and procedures that (i) pertain to the maintenance of
records that, in reasonable detail, accurately and fairly reflect the
transactions and dispositions of the assets of the company; (ii) provide
reasonable assurance that transactions are recorded as necessary to permit
preparation of financial statements in accordance with generally accepted
accounting principles, and that receipts and expenditures of the company are
being made only in accordance with authorizations of management and directors of
the company; and (iii) provide reasonable assurance regarding prevention or
timely detection of unauthorized acquisition, use, or disposition of the
companys assets that could have a material effect on the financial statements.

Because of its inherent limitations,
internal control over financial reporting may not prevent or detect
misstatements. Also, projections of any evaluation of effectiveness to future
periods are subject to the risk that controls may become inadequate because of
changes in conditions, or that the degree of compliance with the policies or
procedures may deteriorate.

/s/ PricewaterhouseCoopers LLPSeattle,
WashingtonJune 14, 2012

3

---



QUANTUM
CORPORATIONCONSOLIDATED BALANCE
SHEETS(In thousands, except par value)

|                                                                                                                                                                                                       |  | March
      31,2012 |          | March
      31,2011
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |  | ------------------- | -------- | -------------------
|Assets                                                                                                                                                                                                 |  |                     |          |                    
|Current
      assets:                                                                                                                                                                                  |  |                     |          |                    
|Cash and cash
      equivalents                                                                                                                                                                        |  | $                   | 51,261   |                    
|Restricted cash                                                                                                                                                                                        |  |                     | 4,230    |                    
|Accounts receivable, net of
      allowance for doubtful accounts of $217 and $403, respectively                                                                                                       |  |                     | 110,840  |                    
|Manufacturing
      inventories                                                                                                                                                                        |  |                     | 61,111   |                    
|Service parts
      inventories                                                                                                                                                                        |  |                     | 39,050   |                    
|Deferred income
taxes                                                                                                                                                                                  |  |                     | 5,295    |                    
|Other current assets                                                                                                                                                                                   |  |                     | 9,434    |                    
|Total current assets                                                                                                                                                                                   |  |                     | 281,221  |                    
|Long-term assets:                                                                                                                                                                                      |  |                     |          |                    
|Property and equipment, less
      accumulated depreciation                                                                                                                                            |  |                     | 25,440   |                    
|Amortizable intangible assets,
      less accumulated amortization                                                                                                                                     |  |                     | 25,763   |                    
|In-process research and
      development                                                                                                                                                              |  |                     | 349      |                    
|Goodwill                                                                                                                                                                                               |  |                     | 55,613   |                    
|Other long-term
    assets                                                                                                                                                                             |  |                     | 6,962    |                    
|Total long-term assets                                                                                                                                                                                 |  |                     | 114,127  |                    
|                                                                                                                                                                                                       |  | $                   | 395,348  |                    
|Liabilities and Stockholders
      Deficit                                                                                                                                                            |  |                     |          |                    
|Current
      liabilities:                                                                                                                                                                             |  |                     |          |                    
|Accounts payable                                                                                                                                                                                       |  | $                   | 56,304   |                    
|Accrued warranty                                                                                                                                                                                       |  |                     | 7,586    |                    
|Deferred revenue,
      current                                                                                                                                                                        |  |                     | 93,441   |                    
|Current portion of long-term
      debt                                                                                                                                                                |  |                     |         |                    
|Accrued restructuring
      charges                                                                                                                                                                    |  |                     | 1,752    |                    
|Accrued compensation                                                                                                                                                                                   |  |                     | 31,971   |                    
|Income taxes payable                                                                                                                                                                                   |  |                     | 1,133    |                    
|Other accrued
      liabilities                                                                                                                                                                        |  |                     | 17,866   |                    
|Total current liabilities                                                                                                                                                                              |  |                     | 210,053  |                    
|Long-term
      liabilities:                                                                                                                                                                           |  |                     |          |                    
|Deferred revenue,
      long-term                                                                                                                                                                      |  |                     | 36,430   |                    
|Deferred income
taxes                                                                                                                                                                                  |  |                     | 4,564    |                    
|Long-term debt                                                                                                                                                                                         |  |                     | 49,495   |                    
|Convertible subordinated
      debt                                                                                                                                                                    |  |                     | 135,000  |                    
|Other long-term
      liabilities                                                                                                                                                                      |  |                     | 6,486    |                    
|Total long-term liabilities                                                                                                                                                                            |  |                     | 231,975  |                    
|Commitments and contingencies                                                                                                                                                                          |  |                     |          |                    
|Stockholders deficit:                                                                                                                                                                                 |  |                     |          |                    
|Preferred stock:                                                                                                                                                                                       |  |                     |          |                    
|Preferred stock, 20,000 shares authorized; no shares issued as of March
      31, 2012and March 31, 2011                                                                                               |  |                     |         |                    
|Common stock:                                                                                                                                                                                          |  |                     |          |                    
|Common stock, $0.01 par value; 1,000,000 shares authorized; 236,402 and
      227,311                           
      shares issued and outstanding as of March 31, 2012 and 2011,
      respectively |  |                     | 2,364    |                    
|Capital in excess of par value                                                                                                                                                                         |  |                     | 409,770  |                    
|Accumulated deficit                                                                                                                                                                                    |  |                     | (465,397 | )                  
|Accumulated other comprehensive income                                                                                                                                                                 |  |                     | 6,583    |                    
|Stockholders deficit                                                                                                                                                                                  |  |                     | (46,680  | )                  
|                                                                                                                                                                                                       |  | $                   | 395,348  |                    

The accompanying notes are an integral
part of these Consolidated Financial Statements.

4

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QUANTUM
CORPORATIONCONSOLIDATED STATEMENTS OF
OPERATIONS(In thousands, except per
share data)

|                                                                 |  | For the year ended March
      31,
|---------------------------------------------------------------- |  | ----------------------------------
|                                                                 |  | 2012                              
|Product revenue                                                  |  | $                                 
|Service revenue                                                  |  |                                   
|Royalty revenue                                                  |  |                                   
|Total revenue                                                    |  |                                   
|Product cost of revenue                                          |  |                                   
|Service cost of revenue                                          |  |                                   
|Restructuring charges (benefit) related to
      cost of revenue |  |                                   
|Total cost of
revenue                                            |  |                                   
|Gross margin                                                     |  |                                   
|Operating expenses:                                              |  |                                   
|Research and development                                         |  |                                   
|Sales and marketing                                              |  |                                   
|General
      and administrative                                 |  |                                   
|Restructuring
charges                                            |  |                                   
|Total operating expenses                                         |  |                                   
|Gain
      on sale of patents                                    |  |                                   
|Income from operations                                           |  |                                   
|Other income and expense                                         |  |                                   
|Interest expense                                                 |  |                                   
|Gain
      (loss) on debt extinguishment, net of costs           |  |                                   
|Income (loss) before income taxes                                |  |                                   
|Income tax provision                                             |  |                                   
|Net income (loss)                                                |  | $                                 
|Net
      income (loss) per share:                               |  |                                   
|Basic                                                            |  | $                                 
|Diluted                                                          |  |                                   
|                                                                 |  |                                   
|Weighted average shares:                                         |  |                                   
|Basic                                                            |  |                                   
|Diluted                                                          |  |                                   

The accompanying notes are an integral
part of these Consolidated Financial Statements.

5

---



QUANTUM
CORPORATIONCONSOLIDATED STATEMENTS OF
COMPREHENSIVE INCOME (LOSS)(In
thousands)

|                                                                                                                                                                 |  | For the year ended March
      31,
|---------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | ----------------------------------
|                                                                                                                                                                 |  | 2012                              
|Net income (loss)                                                                                                                                                |  | $                                 
|Other comprehensive income
      (loss), net of taxes:                                                                                                           |  |                                   
|Foreign currency translation adjustments                                                                                                                         |  |                                   
|Net unrealized gain (loss) on revaluation of long-term intercompany
      balances,                    
      net of taxes of $(52), $(37) and $10, respectively |  |                                   
|Total
      other comprehensive income (loss)                                                                                                                    |  |                                   
|Total comprehensive income (loss)                                                                                                                                |  | $                                 

The accompanying notes are an integral
part of these Consolidated Financial Statements.

6

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QUANTUM
CORPORATIONCONSOLIDATED STATEMENTS OF
CASH FLOWS(In thousands)

|                                                                                                      |  | For the year
      ended March 31,
|----------------------------------------------------------------------------------------------------- |  | ----------------------------------
|                                                                                                      |  | 2012                              
|Cash flows from operating
    activities:                                                             |  |                                   
|Net income (loss)                                                                                     |  | $                                 
|Adjustments to reconcile net
      income (loss) to net cash provided by        operating activities: |  |                                   
|Depreciation                                                                                          |  |                                   
|Amortization                                                                                          |  |                                   
|Service parts lower of cost or market adjustment                                                      |  |                                   
|(Gain) loss on debt extinguishment                                                                    |  |                                   
|Deferred income taxes                                                                                 |  |                                   
|Share-based compensation                                                                              |  |                                   
|Other non-cash writeoffs                                                                              |  |                                   
|Changes in assets and liabilities, net of effect of acquisition:                                      |  |                                   
|Accounts receivable                                                                                   |  |                                   
|Manufacturing inventories                                                                             |  |                                   
|Service parts inventories                                                                             |  |                                   
|Accounts payable                                                                                      |  |                                   
|Accrued warranty                                                                                      |  |                                   
|Deferred revenue                                                                                      |  |                                   
|Accrued restructuring charges                                                                         |  |                                   
|Accrued compensation                                                                                  |  |                                   
|Income taxes payable                                                                                  |  |                                   
|Other assets and liabilities                                                                          |  |                                   
|Net
      cash provided by operating activities                                                       |  |                                   
|Cash flows from investing
    activities:                                                             |  |                                   
|Purchases of property and equipment                                                                   |  |                                   
|(Increase) decrease in restricted cash                                                                |  |                                   
|Return of principal from other investments                                                            |  |                                   
|Payment for business acquisition, net of cash acquired                                                |  |                                   
|Net
      cash used in investing activities                                                           |  |                                   
|Cash flows from financing
    activities:                                                             |  |                                   
|Borrowings of long-term debt, net                                                                     |  |                                   
|Repayments of long-term debt                                                                          |  |                                   
|Borrowings of convertible subordinated debt, net                                                      |  |                                   
|Repayments of convertible subordinated debt                                                           |  |                                   
|Payment of taxes due upon vesting of restricted stock                                                 |  |                                   
|Proceeds from issuance of common stock                                                                |  |                                   
|Net
      cash used in financing activities                                                           |  |                                   
|Effect of exchange rate changes on cash and
      cash equivalents                                    |  |                                   
|Net increase (decrease) in cash and cash equivalents                                                  |  |                                   
|Cash and cash equivalents at beginning of
      period                                                |  |                                   
|Cash
      and cash equivalents at end of period                                                      |  | $                                 
|Supplemental disclosure of cash flow
      information:                                               |  |                                   
|Fair value of common stock issued for business combination                                            |  | $                                 
|Purchases of property and equipment included in accounts payable                                      |  |                                   
|Cash
      paid during the year for:                                                                  |  |                                   
|Interest                                                                                              |  |                                   
|Income taxes, net of refunds                                                                          |  |                                   

The accompanying notes are an integral
part of these Consolidated Financial Statements.

7

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QUANTUM
CORPORATIONCONSOLIDATED STATEMENTS OF
STOCKHOLDERS DEFICIT(In thousands)

|                                            |                        |         |            | Capitalin Excess ofPar
      Value |       | RetainedDeficit |   | AccumulatedOtherComprehensiveIncome |  | Total
|------------------------------------------- | ---------------------- | ------- | ---------- | ---------------------------------- | ----- | --------------- | - | ----------------------------------- |  | -----
|                                            |                       
|                                            | **Common
      Stock**
|                                            | **Shares**             |         | **Amount**
|Balances as of March 31, 2009               |                        | 210,231 |            | $                                  | 2,102 |                 | $ | 349,850                             |  | $    
|Net
      income                            |                        |        |            |                                    |      |                 |   |                                    |  |      
|Foreign currency
      translation          |                        |         |            |                                    |       |                 |   |                                     |  |      
|adjustments                                 |                        |        |            |                                    |      |                 |   |                                    |  |      
|Net
      unrealized gain on revaluation    |                        |         |            |                                    |       |                 |   |                                     |  |      
|of long-term intercompany                   |                        |         |            |                                    |       |                 |   |                                     |  |      
|balance, net of tax of $10                  |                        |        |            |                                    |      |                 |   |                                    |  |      
|Shares issued under
      employee stock    |                        |         |            |                                    |       |                 |   |                                     |  |      
|incentive plans, net                        |                        | 4,715   |            |                                    | 47    |                 |   | 1,735                               |  |      
|Share-based compensation expense            |                        |        |            |                                    |      |                 |   | 9,789                               |  |      
|Balances as of March 31, 2010               |                        | 214,946 |            |                                    | 2,149 |                 |   | 361,374                             |  |      
|Net
      income                            |                        |        |            |                                    |      |                 |   |                                    |  |      
|Foreign currency
      translation          |                        |         |            |                                    |       |                 |   |                                     |  |      
|adjustments                                 |                        |        |            |                                    |      |                 |   |                                    |  |      
|Net
      unrealized loss on revaluation of |                        |         |            |                                    |       |                 |   |                                     |  |      
|long-term intercompany balance,             |                        |         |            |                                    |       |                 |   |                                     |  |      
|net of tax of $(37)                         |                        |        |            |                                    |      |                 |   |                                    |  |      
|Shares issued under
      employee stock    |                        |         |            |                                    |       |                 |   |                                     |  |      
|purchase plan                               |                        | 3,234   |            |                                    | 32    |                 |   | 3,912                               |  |      
|Shares
      issued under employee stock    |                        |         |            |                                    |       |                 |   |                                     |  |      
|incentive plans, net                        |                        | 9,131   |            |                                    | 92    |                 |   | 10,204                              |  |      
|Share-based
      compensation expense      |                        |        |            |                                    |      |                 |   | 10,421                              |  |      
|Balances as of March 31,
      2011         |                        | 227,311 |            |                                    | 2,273 |                 |   | 385,911                             |  |      
|Net loss                                    |                        |        |            |                                    |      |                 |   |                                    |  |      
|Foreign
      currency translation          |                        |         |            |                                    |       |                 |   |                                     |  |      
|adjustments                                 |                        |        |            |                                    |      |                 |   |                                    |  |      
|Net unrealized loss
      on revaluation of |                        |         |            |                                    |       |                 |   |                                     |  |      
|long-term intercompany balance,             |                        |         |            |                                    |       |                 |   |                                     |  |      
|net of tax of $(52)                         |                        |        |            |                                    |      |                 |   |                                    |  |      
|Shares
      issued under employee stock    |                        |         |            |                                    |       |                 |   |                                     |  |      
|purchase plan                               |                        | 3,036   |            |                                    | 31    |                 |   | 5,012                               |  |      
|Shares issued under
      employee stock    |                        |         |            |                                    |       |                 |   |                                     |  |      
|incentive plans, net                        |                        | 5,084   |            |                                    | 51    |                 |   | 2,352                               |  |      
|Shares
      issued in connection with      |                        |         |            |                                    |       |                 |   |                                     |  |      
|business acquisition                        |                        | 971     |            |                                    | 9     |                 |   | 2,758                               |  |      
|Share-based
      compensation expense      |                        |        |            |                                    |      |                 |   | 13,737                              |  |      
|Balances as of March 31,
      2012         |                        | 236,402 |            | $                                  | 2,364 |                 | $ | 409,770                             |  | $    

The accompanying notes are an integral
part of these Consolidated Financial Statements.

8

---



QUANTUM CORPORATION

NOTES TO CONSOLIDATED FINANCIAL
STATEMENTS

NOTE 1: BASIS OF PRESENTATION

Quantum Corporation (Quantum, the
Company, us or we), founded in 1980, is a global expert in data protection
and big data management. We provide solutions for storing and protecting
information in physical, virtual, cloud and big data environments that are
designed to help customers be certain they are maximizing the value of their
data over its entire lifecycle. With our solutions, customers can better adapt
in a world of continuing change by keeping and protecting more data for a longer
period of time while reducing costs and increasing return on investment. We work
closely with a broad network of distributors, value-added resellers (VARs),
direct marketing resellers (DMRs), original equipment manufacturers (OEMs)
and other suppliers to meet customers evolving data protection and big data
management needs. Our stock is traded on the New York Stock Exchange under the
symbol QTM.

The accompanying Consolidated Financial
Statements include the accounts of Quantum and our wholly-owned subsidiaries. On
June 13, 2011, we acquired Pancetera Software, Inc. (Pancetera), and
Panceteras results of operations are included in our Consolidated Statements of
Operations from that date. All intercompany accounts and transactions have been
eliminated. The preparation of our Consolidated Financial Statements in
conformity with generally accepted accounting principles (GAAP) in the U.S.
requires management to make estimates and assumptions that affect the reported
amount of assets and liabilities at the date of the financial statements and the
reported amount of revenues and expenses during the period. We base estimates on
historical experience and on various assumptions about the future that are
believed to be reasonable based on available information. Our reported financial
position or results of operations may be materially different under different
conditions or when using different estimates and assumptions, particularly with
respect to significant accounting policies, which are discussed below. In the
event that estimates or assumptions prove to differ from actual results,
adjustments are made in the current period to reflect this current information.

NOTE 2: SUMMARY OF SIGNIFICANT
ACCOUNTING POLICIES

Revenue Recognition

Revenue consists of sales of hardware,
software and services, as well as royalties we earn for the license of certain
intellectual property. Revenue is recognized from the sale of products and
services when it is realized or realizable and earned. Revenue is considered
realized and earned when: persuasive evidence of an arrangement exists; delivery
has occurred or services have been rendered; the price to the buyer is fixed or
determinable; and when collectibility is reasonably assured. Royalty revenue is
recognized when earned or amounts can be reasonably estimated.

Product Revenue 
Hardware

Revenue for hardware products sold to
distributors, VARs, DMRs, OEMs and end users is generally recognized upon
shipment. When significant post-delivery obligations exist, the related revenue
is deferred until such obligations are fulfilled. If there are customer
acceptance criteria in the contract, we recognize revenue upon end user
acceptance, which typically occurs after delivery and installation are
completed.

In the period revenue is recognized,
allowances are provided for estimated future price adjustments, such as rebates,
price protection and future product returns. These allowances are based on
programs in existence at the time revenue is recognized, plans regarding future
price adjustments, the customers master agreements and historical product
return rates. Since we have historically been able to reliably estimate the
amount of allowances required, we recognize revenue, net of projected
allowances, upon shipment to our customers. If we were unable to reliably
estimate the amount of revenue adjustments in any specific reporting period,
then we would be required to defer recognition of the revenue until the rights
had lapsed and we were no longer under any obligation to reduce the price or
accept the return of the product.

9

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Product Revenue 
Software

Software revenue is generally recognized
upon shipment or electronic delivery and when vendor-specific objective evidence
(VSOE) of fair value for undelivered elements exists. For software
arrangements with multiple elements, the residual method is used to determine
the amount of product revenue to be recognized. Under the residual method, the
VSOE of fair value for the undelivered elements is deferred and the remaining
portion of the arrangement consideration is recognized as product revenue,
assuming all other revenue recognition criteria of appropriate revenue guidance
have been met. Revenue from post-contract customer support agreements, which
entitle customers to both telephone support and any unspecified upgrades and
enhancements during the term of the agreement, is recognized ratably over the
term of the support agreement.

We license certain software to customers
under licensing agreements that allow those customers to embed our software into
specific products they offer. As consideration, licensees pay us a fee based on
the amount of sales of their products that incorporate our software. On a
periodic and timely basis, the licensees provide us with reports listing their
sales to end users for which they owe us license fees. As the reports
substantiate delivery has occurred, we recognize revenue based on the
information in these reports or when amounts can be reasonably
estimated.

Service Revenue

Revenue for service is generally
recognized upon services being rendered. Service revenue consists of customer
field support agreements for our hardware products, installation, professional
services and out-of-warranty repairs. For customer field support agreements,
revenue equal to the separately stated price of these service contracts for our
hardware products is initially deferred and recognized as revenue ratably over
the contract period. Installation and professional services are not considered
essential to the functionality of our products as these services do not alter
the product capabilities, do not require specialized skills and may be performed
by our customers or other vendors. Installation and professional services are
recognized upon completion. Out-of-warranty repair revenue is recognized upon
completion of the repair.

Royalty Revenue

We license certain intellectual property
to third party manufacturers under arrangements that are represented by master
contracts. The master contracts give the third party manufacturers rights to the
intellectual property which include allowing them to either manufacture or
include the intellectual property in products for resale. As consideration, the
licensees pay us a per-unit royalty for sales of their products that incorporate
our intellectual property. On a periodic and timely basis, the licensees provide
us with reports listing units sold to end users subject to the royalties. As the
reports substantiate delivery has occurred, we recognize revenue based on the
information in these reports or when amounts can be reasonably
estimated.

Multiple Element
Arrangements

For multiple deliverable revenue
arrangements with customers which are not subject to software revenue guidance,
we separate the deliverables based on specific criteria, assign an estimated
selling price to each deliverable based on the selling price hierarchy using
VSOE, third-party evidence of selling price (TPE) or estimated selling price
(ESP) and allocate the total arrangement consideration using the relative
selling price method. When VSOE cannot be established we attempt to establish
the selling price of each element based on TPE. TPE is determined based on
competitor prices for largely interchangeable products when sold separately.
When we are unable to establish selling price using VSOE or TPE, we use ESP. For
ESP, we consider our discounting and internal pricing practices. Additionally,
for certain transactions we evaluate whether any undelivered elements are
essential to the functionality of the delivered elements in order to determine
the appropriate timing of revenue recognition. If specific criteria are not met,
the arrangement is accounted for as one unit of accounting which results in
revenue being deferred until the earlier of when such criteria are met, when the
last undelivered element is delivered or ratably over the contract term as
appropriate.

Service Cost of Revenue

We classify expenses as service cost of
revenue by estimating the portion of our total cost of revenue that relates to
providing field support to our customers under contract, installation,
integration and repair services. These estimates are based upon a variety of
factors, including the nature of the support activity and the level of
infrastructure required to support the activities from which we earn service
revenue. In the event our service business changes, our estimates of cost of
service revenue may be impacted. Service cost of revenue excludes costs
associated with basic warranty support on new products.

10

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Shipping and Handling Fees

Shipping and handling fees are included in
cost of revenue and were $20.3 million, $22.2 million and $26.1 million in
fiscal 2012, 2011 and 2010, respectively.

Research and Development Costs

Expenditures relating to the development
of new products and processes are expensed as incurred. These costs include
expenditures for employee compensation, materials used in the development
effort, other internal costs, as well as expenditures for third party
professional services. We have determined that technological feasibility for our
software products is reached shortly before the products are released to
manufacturing. Costs incurred after technological feasibility is established
have not been material. We expense software-related research and development
costs as incurred.

Advertising Expense

We expense advertising costs as incurred.
Advertising expense for the years ended March 31, 2012, 2011 and 2010 was $4.3
million, $5.0 million and $3.9 million, respectively.

Restructuring Charges

In recent periods and over the past
several years, we have recorded significant restructuring charges related to the
realignment and restructuring of our business operations. These charges
represent expenses incurred in connection with strategic planning, certain cost
reduction programs and acquisition integrations that we have implemented and
consist of the cost of involuntary termination benefits, facilities charges,
asset write-offs and other costs of exiting activities or geographies.

The charges for involuntary termination
costs and associated expenses often require the use of estimates, primarily
related to the number of employees to be paid severance and the amounts to be
paid, largely based on years of service and statutory requirements. Assumptions
to estimate facility exit costs include the ability to secure sublease income
largely based on market conditions, the likelihood and amounts of a negotiated
settlement for contractual lease obligations and other exit costs. Other
estimates for restructuring charges consist of the realizable value of assets
including associated disposal costs and termination fees with third parties for
other contractual commitments.

Share-Based Compensation

We account for share-based compensation
using the Black-Scholes stock option pricing model to estimate the fair value of
share-based awards at the date of grant. The Black-Scholes model requires the
use of highly subjective assumptions, including expected life, expected
volatility and expected risk-free rate of return. Other reasonable assumptions
could provide differing results. We calculate a forfeiture rate to estimate the
share-based awards that will ultimately vest based on types of awards and
historical experience. Additionally, for awards which are performance based, we
make estimates as to the probability of the underlying performance being
achieved.

Foreign Currency Translation and
Transactions

Assets, liabilities and operations of
foreign offices and subsidiaries are recorded based on the functional currency
of the entity. For a majority of our foreign operations, the functional currency
is the U.S. dollar. The assets and liabilities of foreign offices with a local
functional currency are translated, for consolidation purposes, at current
exchange rates from the local currency to the reporting currency, the U.S.
dollar. The resulting gains or losses are reported as a component of other
comprehensive income. Foreign exchange gains and losses from changes in the
exchange rates underlying intercompany balances that are of a long-term
investment nature are also reported as a component of other comprehensive
income. Assets and liabilities denominated in other than the functional currency
are remeasured each month with the remeasurement gain or loss recorded in other
income and expense in the Consolidated Statements of Operations. Foreign
currency gains and losses recorded in other income and expense were a $0.1
million loss in fiscal 2012, a $0.3 million gain in fiscal 2011 and a $0.6
million loss in fiscal 2010.

11

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Income Taxes

We recognize deferred tax assets and
liabilities due to the effect of temporary differences between the carrying
amounts of assets and liabilities for financial reporting purposes and the
amounts used for income tax purposes. We also reduce deferred tax assets by a
valuation allowance if it is more likely than not that some or all of the
deferred tax asset will not be realized.

We recognize the benefit from a tax
position only if it is more-likely-than-not that the position would be sustained
upon audit based solely on the technical merits of the tax position. The
calculation of our tax liabilities requires judgment related to uncertainties in
the application of complex tax regulations. It is inherently difficult and
subjective to estimate such amounts, as we have to determine the probability of
various possible outcomes. We reevaluate these uncertain tax positions on a
quarterly basis. This evaluation is based on factors including, but not limited
to, changes in facts or circumstances, changes in tax law, effectively settled
issues under audit and new audit activity. A change in recognition or
measurement would result in the recognition of a tax benefit or an additional
tax charge to the provision.

We recognize interest and penalties
related to uncertain tax positions in the income tax provision in the
Consolidated Statements of Operations. To the extent accrued interest and
penalties do not become payable, amounts accrued will be reduced and reflected
as a reduction of the overall income tax provision in the period that such
determination is made.

Cash Equivalents, Restricted Cash and
Other Investments

We consider all highly liquid debt
instruments with a maturity of 90 days or less at the time of purchase to be
cash equivalents. Cash equivalents are carried at fair value, which approximates
their cost.

Restricted cash is comprised of bank
guarantees and similar required minimum balancesthat serve as cash collateral in connection with various items including
insurance requirements, value added taxes, ongoing tax audits and leases in
certain countries.

We also hold investments in private
technology venture limited partnerships. These investments individually
represent voting ownership interests of less than 20%. Ownership interests in
these limited partnerships are accounted for under the equity method unless our
interest is so minor (typically less than 5%) that we have virtually no
influence over the partnership operating and financial policies, in which case
the cost method is used. Currently, our investments in these limited
partnerships are accounted for using the equity method.

Investments in other privately held
companies are accounted for under the cost method unless we hold a significant
stake. We review non-marketable equity investments on a regular basis to
determine if there has been any impairment of value which is other than
temporary by reviewing their financial information, gaining knowledge of any new
financing or other business agreements and assessing their operating viability.

Allowance for Doubtful Accounts

We perform ongoing credit evaluations of
our customers financial condition and, for the majority of our customers,
require no collateral. For customers that do not meet our credit standards, we
often require a form of collateral, such as cash deposits or letters of credit
prior to the completion of a transaction. These credit evaluations require
significant judgment and are based on multiple sources of information. We
analyze such factors as our historical bad debt experience, industry and
geographic concentrations of credit risk, current economic trends and changes in
customer payment terms. We maintain an allowance for doubtful accounts based on
historical experience and expected collectibility of outstanding accounts
receivable. We record bad debt expense in general and administrative expenses.

Manufacturing Inventories

Our manufacturing inventory is stated at
the lower of cost or market, with cost computed on a first-in, first-out
(FIFO) basis. Adjustments to reduce the cost of manufacturing inventory to its
net realizable value, if required, are made for estimated excess, obsolete or
impaired balances. Factors influencing these adjustments include declines in
demand, rapid technological changes, product life cycle and development plans,
component cost trends, product pricing, physical deterioration and quality
issues. Revisions to these adjustments would be required if these factors differ
from our estimates.

12

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Service Parts
InventoriesOur service parts inventories
are stated at the lower of cost or market. We carry service parts because we
generally provide product warranty for 1 to 3 years and earn revenue by
providing enhanced and extended warranty and repair service during and beyond
this warranty period. Service parts inventories consist of both component parts,
which are primarily used to repair defective units, and finished units, which
are provided for customer use permanently or on a temporary basis while the
defective unit is being repaired. Defective parts returned from customers that
can be repaired are repaired and put back into service parts inventories at
their fair value. We record adjustments to reduce the carrying value of service
parts inventory to its net realizable value, and we dispose of parts with a net
realizable value of zero. Factors influencing these adjustments include product
life cycles, end of service life plans and volume of enhanced or extended
warranty service contracts. Estimates of net realizable value involve
significant estimates and judgments about the future, and revisions would be
required if these factors differ from our estimates.

Property and Equipment

Property and equipment are carried at
cost, less accumulated depreciation and amortization, computed on a
straight-line basis over the estimated useful lives of the assets as follows:

| | Machinery and
      equipment | 3 to 5 years   
| | ----------------------------- | ---------------
| | Computer equipment            | 3 to 5 years   
| | ERP software                  | 10 years       
| | Other software                | 3 years        
| | Furniture and
      fixtures  | 5 years        
| | Other office equipment        | 5 years        
| | Leasehold
      improvements  | Life of
  lease

Amortizable Intangible and Other
Long-lived Assets

We review amortizable intangible and other
long-lived assets (long-lived assets) for impairment whenever events or
changes in circumstances indicate the carrying amount of such assets may not be
recoverable. The company operates as a single reporting unit for business and
operating purposes, and our impairment evaluation also treats the company as a
single reporting unit. Impairment indicators we consider include adverse changes
in the business climate that could affect the value of our long-lived assets,
changes in our stock price and resulting market capitalization relative to book
value, downward revisions in our revenue outlook, decreases or slower than
expected growth in sales of products and relative weakness in customer channels.
If we indentify impairment indicators, we evaluate recoverability using an
undiscounted cash flow approach. Estimates of future cash flows incorporate
company forecasts and our expectations of future use of our long-lived assets,
and these factors are impacted by market conditions. If impairment is indicated,
an impairment charge is recorded to write the long-lived assets down to their
estimated fair value.

Goodwill

We evaluate goodwill for impairment
annually during the fourth quarter of our fiscal year, or more frequently when
indicators of impairment are present. During fiscal 2012, we early adopted the
accounting guidance that allows entities to perform a qualitative assessment to
determine whether a quantitative calculation is necessary. As a result, we may
perform a qualitative test, a quantitative test, or both for the annual
impairment assessment. Some of the impairment indicators we consider include
changes in our stock price and resulting market capitalization relative to book
value, changes in the business climate, business strategy or product mix,
changes to the long-term economic outlook and testing long-lived assets for
recoverability. We operate as a single reporting unit and consider the company
as a whole when reviewing these factors. If impairment is indicated, a goodwill
impairment charge is recorded to write the goodwill down to its implied fair
value.

Accrued WarrantyWe generally warrant our hardware products against defects for
periods ranging from 1 to 3 years from the date of sale. Our tape automation
systems and disk systems may carry service agreements with customers that choose
to extend or upgrade the warranty service. We provide repair services from our
facility in Colorado Springs, Colorado as well as multiple third party providers
inside and outside of the U.S. We use a combination of internal resources and
third party service providers to supply field service and support. We continue
to evaluate repair sites, and any resulting actions taken may affect the future
costs of repair. If the actual costs were to differ significantly from our
estimates, we would record the impact of these unforeseen costs or cost
reductions in subsequent periods.

13

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We estimate future failure rates based
upon historical product failure trends as well as anticipated future failure
rates if believed to be significantly different from historical trends.
Similarly, we estimate future costs of repair based upon historical trends and
anticipated future costs if they are expected to significantly differ, for
example due to negotiated agreements with third parties. We use a consistent
model and exercise considerable judgment in determining the underlying
estimates. Our model requires an element of subjectivity for all of our
products. For example, historical rates of return are not completely indicative
of future return rates and we must therefore exercise judgment with respect to
future deviations from our historical return rate. When actual failure rates
differ significantly from our estimates, we record the impact in subsequent
periods and update our assumptions and forecasting models accordingly. As our
newer products mature, we are able to improve our estimates with respect to
these products. It is reasonably likely that assumptions will be updated for
failure rates and, therefore, our accrued warranty estimate could change in the
future.

Business
Combinations

We allocate the purchase price paid to the
assets acquired and liabilities assumed in a business combination at their
estimated fair values as of the acquisition date. Any excess purchase price
above the identified net tangible and intangible assets and assumed liabilities
is allocated to goodwill. We consider fair value to be the price that would be
received to sell an asset or paid to transfer a liability in an orderly
transaction between market participants at the measurement date. We estimate
fair value using the fair value hierarchy for the tangible and intangible assets
acquired as well as liabilities and contingencies assumed from the acquired
company.

Derivative Financial Instruments

We recognize all derivatives, whether
designated in hedging relationships or not, on the balance sheet at fair value.
If the derivative is designated as a fair value hedge, the changes in the fair
value of the derivative and the hedged item are recognized in earnings. If the
derivative is designated as a cash flow hedge, changes in the fair value of the
derivative are recorded in other comprehensive income and are recognized in the
Consolidated Statements of Operations when the hedged item affects earnings.
Derivatives not designated or qualifying as a hedging instrument are adjusted to
fair value through earnings. We may, from time to time, enter into derivative
instruments to hedge against known or forecasted market exposures.

Common Stock Repurchases

During fiscal 2000, the Board of Directors
authorized us to repurchase up to $700 million of our common stock in open
market or private transactions. As of March 31, 2012 and 2011, there was $87.9
million remaining on our authorization to repurchase Quantum common stock. Our
ability to repurchase our common stock is restricted unless we meet certain
thresholds under the terms of the Wells Fargo credit agreement (WF credit
agreement).

Fair Value of Financial
Instruments

We use exit prices, that is the price to
sell an asset or transfer a liability, to measure assets and liabilities that
are within the scope of the fair value measurements guidance. We classify these
assets and liabilities based on the following fair value hierarchy:

| | Level 1:     | Quoted (observable) market prices in
      active markets for identical assets or liabilities.                                                                                                                                                                                                                      
| | ------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
| | Level 2:     | Observable inputs other than Level 1,
      such as quoted prices for similar assets or liabilities; quoted prices in
      markets that are not active; or other inputs that are observable or can be
      corroborated by observable market data for substantially the full term of
      the asset or liability.
| | Level
    3: | Prices or valuations that require
      inputs that are both significant to the fair value measurement and
      unobservable.                                                                                                                                                                                      

The assets measured and recorded at fair
value on a recurring basis consist of money market funds which are valued using
quoted market prices at the respective balance sheet dates and are level 1 fair
value measurements (in thousands):

As of March 31,2012
    
    2011Money market
    funds
    $
    37,776
    
    $
    68,560


We have certain non-financial assets that
are measured at fair value on a non-recurring basis when there is an indicator
of impairment, and they are recorded at fair value only when an impairment is
recognized. These assets include property and equipment, amortizable intangible
assets, in-process research and development (IPR&D) and goodwill. We did
not record impairments to any non-financial assets in fiscal 2012 or fiscal
2011. We do not have any non-financial liabilities measured and recorded at fair
value on a non-recurring basis.

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We have financial liabilities for which we
are obligated to repay the carrying value, unless the holder agrees to a lesser
amount. The carrying value and fair value of these financial liabilities were as
follows (in thousands):

| |                                        |  | As of March
      31,
| | -------------------------------------- |  | ---------------------
| |                                        |  | 2012                 
| |                                        |  | Carrying
      Value 
| | Senior secured revolving
      debt(1) |  | $                    
| | Senior secured term debt(2)            |  |                      
| | Convertible subordinated
      debt(3) |  |                      

| | (1) |  | Fair
      value based on outstanding borrowings and market interest
  rates.              
| | --- |  | -------------------------------------------------------------------------------------------
| | (2) |  | Fair
      value based on non-binding broker quotes using current market
      information.
| | (3) |  | Fair
      value based on quoted market
prices.                                            

Risks and Uncertainties

As is typical in the information storage
industry, a significant portion of our customer base is concentrated among a
small number of OEMs, distributors and large VARs. The loss of any one of our
more significant customers, or a significant decrease in the sales volume with
one of these significant customers, could have a material adverse effect on our
results of operations and financial condition. Furthermore, if there is a
downturn in general economic conditions, the resulting effect on IT spending
could also have a material adverse effect on our results of operations and
financial condition. We also face risks and uncertainties since our competitors
in one area may be customers or suppliers in another.

A limited number of products comprise a
significant majority of our sales, and due to increasingly rapid technological
change in the industry, our future operating results depend on our ability to
develop and successfully introduce new products.

Concentration of Credit Risk

We currently invest our excess cash in
deposits with major banks and in money market funds. In the past, we have also
held investments in short-term debt securities of companies with strong credit
ratings from a variety of industries, and we may make investments in these
securities in the future. We have not experienced any material losses on these
investments and limit the amount of credit exposure to any one issuer and to any
one type of investment.

We sell products to customers in a wide
variety of industries on a worldwide basis. In countries or industries where we
are exposed to material credit risk, we may require collateral, including cash
deposits and letters of credit prior to the completion of a transaction. We do
not believe we have significant credit risk beyond that provided for in the
financial statements in the ordinary course of business.

Sales to our top five customers
represented 34% of revenue in fiscal 2012 compared to 33% of revenue in fiscal
2011 and 37% of revenue in fiscal 2010. We had no customers that comprised 10%
or greater of revenue in fiscal 2012. Sales to our largest customer, Dell Inc.
(Dell), were 10% of revenue in fiscal 2011 compared to 13% of revenue in
fiscal 2010.

Recently Adopted Accounting
Pronouncements

In the first quarter of fiscal 2012, we
adopted the goodwill impairment guidance for reporting units with zero or
negative carrying amounts. Adoption of this standard did not have an impact on
our financial position or results of operations.

In the first quarter of fiscal 2012, we
adopted the guidance for disclosure of supplementary pro forma information for
business combinations. Adoption of this standard did not have an impact on our
financial position or results of operations, other than the additional
disclosures included in the notes to the Consolidated Financial
Statements.

In the fourth quarter of fiscal 2012, we
early adopted the guidance regarding the presentation of other comprehensive
income. We elected to present other comprehensive income in two separate but
consecutive statements of net income and its components followed immediately by
a statement of other comprehensive income (loss). Adoption of this standard did
not have an impact on our financial position or results of operations, other
than the additional statement in the Consolidated Financial
Statements.

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In the fourth quarter of fiscal 2012, we
early adopted the guidance that allows entities to perform a qualitative
assessment for step one goodwill impairment testing. Adoption of this standard
did not have an impact on our financial position or results of operations.

Recent Accounting
Pronouncements

In May 2011, the Financial Accounting
Standards Board (FASB) issued Accounting Standards Update No. 2011-04,Fair Value Measurement (Topic 820): Amendments
to Achieve Common Fair Value Measurement and Disclosure Requirements in U.S.
GAAP and IFRSs(ASU 2011-04), which amends
the accounting standards for fair value measurements and disclosures. ASU
2011-04 provides clarifications about the application of existing fair value
measurement and disclosure requirements. In addition, ASU 2011-04 changes how to
measure fair value of financial instruments managed within a portfolio and how
to apply premiums and discounts. There are also additional disclosures required.
ASU 2011-04 is effective for fiscal years, and interim periods within those
years, beginning after December 15, 2011. We will apply this standard beginning
in fiscal 2013 and do not anticipate adoption will impact our statements of
financial position or results of operations.

NOTE 3: ACQUISITION

On June 13, 2011, in order to enhance our
product offerings and technology portfolio we acquired Pancetera pursuant to a
statutory merger in exchange for approximately $11.0 million, comprised of $8.2
million in cash and $2.8 million in Quantum common stock. We acquired all
outstanding shares of Pancetera and assumed all of Panceteras outstanding
unvested stock options according to the option exchange ratio defined in the
merger agreement with Pancetera. We also assumed unvested restricted Pancetera
common stock in accordance with the merger agreement. Panceteras results of
operations are included in our Consolidated Statements of Operations and Cash
Flows from the June 13, 2011 acquisition date.

The acquisition was recorded under the
acquisition method of accounting, resulting in the purchase price being
allocated to the assets acquired and liabilities assumed based on their
estimated fair values. The excess of the purchase price over the assets acquired
and liabilities assumed was recorded as goodwill. The allocation of assets
acquired and liabilities assumed is set forth below (in thousands):

| | Current assets                      | $ | 46     |  
| | ----------------------------------- | - | ------ | -
| | Property and equipment              |   | 37     |  
| | Amortizable intangible assets       |   | 1,795  |  
| | In-process research and development |   | 349    |  
| | Goodwill                            |   | 8,843  |  
| | Current liabilities                 |   | (116   | )
| | Total purchase
      price          | $ | 10,954 |  

In performing our purchase price
allocation, we considered, among other factors, our intention for future use of
acquired assets, analyses of historical financial performance and estimates of
future performance of Panceteras existing and future products. The fair value
of current assets, property and equipment and current liabilities was based on
market prices at the acquisition date. The fair value of amortizable intangible
assets and IPR&D was based, in part, on a valuation using a discounted cash
flow approach and other valuation techniques as well as managements estimates
and assumptions.

The amortizable intangible assets are all
related to developed technology and are included in purchased technology within
Note 5 Intangible Assets and Goodwill. Purchased technology, which comprises
products that have reached technological feasibility, was primarily related to
SmartRead®. SmartRead is patented technology, primarily comprised of
a set of algorithms that reduce storage input-output when performing maintenance
tasks such as backup, replication or migration of virtual machines. Pancetera
products containing the SmartRead technology included SmartViewTM
and SmartMotionTM, which have been rebranded as vmPRO software
solutions. Purchased technology intangible assets also include a combination of
Pancetera processes, patents and trade secrets related to the design and
development of these products. This proprietary know-how can be leveraged to
develop new technology and improve our products. The SmartRead purchased
technology intangible asset has an amortization period of four years.

16

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IPR&D represents incomplete Pancetera
research and development projects that had not reached technological feasibility
as of the acquisition date. Due to the nature of IPR&D, the expected life is
indeterminate and we periodically evaluate for attainment of technological
feasibility or impairment. Technological feasibility is established when an
enterprise has completed all planning, designing, coding and testing activities
that are necessary to establish that a product can be produced to meet its
design specifications including functions, features and technical performance
requirements. The value assigned to IPR&D was determined by considering the
importance of each project to our overall development plan, estimating costs to
develop the purchased IPR&D into commercially viable products, estimating
the resulting net cash flows from the projects when completed and discounting
the net cash flows using a discount rate of 18% to their present value based on
the percentage of completion of the IPR&D projects.

The goodwill as a result of this
acquisition is not expected to be deductible for tax purposes. In addition, we
incurred acquisition expenses of $0.3 million during fiscal 2012 which are
included in general and administrative expense in our Consolidated Statements of
Operations. The following unaudited supplemental pro forma information presents
the combined results of operations of Quantum and Pancetera as if the
acquisition had occurred as of the beginning of fiscal 2011 (in thousands):

|                   | As of March 31
|------------------ | --------------
|                   | 2012          
|Pro forma
revenue  | $             
|Pro forma net loss |               

NOTE 4: BALANCE SHEET DETAILS

Cash, cash equivalents and restricted cash
consisted of (in thousands):

|                        | As of March 31
|----------------------- | --------------
|                        | 2012          
|Cash                    | $             
|Certificates of deposit |               
|Money market
    funds  |               
|                        | $             

Manufacturing inventories consisted of (in
thousands):

|                                    | As of March 31
|----------------------------------- | --------------
|                                    | 2012          
|Finished goods                      | $             
|Work in process                     |               
|Materials and purchased
      parts |               
|                                    | $             

Service parts inventories consisted of (in
thousands):

|                | As of March 31
|--------------- | --------------
|                | 2012          
|Finished goods  | $             
|Component parts |               
|                | $             

Property and equipment consisted of (in
thousands):

|                              | As of March 31
|----------------------------- | --------------
|                              | 2012          
|Machinery and
      equipment | $             
|Furniture and fixtures        |               
|Leasehold
      improvements  |               

|                               | As of March 31
|------------------------------ | --------------
|                               | 2012          
|                               |               
|Less: accumulated depreciation |               
|                               | $             

17

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NOTE 5: INTANGIBLE ASSETS AND
GOODWILL

Intangible Assets

Acquired intangible assets are amortized
over their estimated useful lives, which generally range from one to eight
years. In estimating the useful lives of intangible assets, we considered the
following factors:

- The cash flow projections used to estimate the
  useful lives of the intangible assets showed a trend of growth that was
  expected to continue for an extended period of time;
- Our tape automation products, disk systems and
  software, in particular, have long development cycles; these products have
  experienced long product life cycles; and
- Our ability to leverage core technology into data
  protection and big data and archive solutions and, therefore, to extend the
  lives of these technologies.

Acquired IPR&D is amortized over its
estimated useful life once technological feasibility is reached. If IPR&D is
determined to not have technological feasibility or is abandoned, we write off
the IPR&D in that period.

Following is the weighted average
amortization period for our amortizable intangible assets:

|                         | Amortization
|------------------------ | ------------
|                         | (Years)     
|Purchased
    technology | 6.2         
|Trademarks               | 6.0         
|Customer lists           | 7.1         
|All intangible assets    | 6.5         

Intangible amortization within our
Consolidated Statements of Operations for the years ended March 31, 2012, 2011
and 2010 follows (in thousands):

|                             |  | For the year ended March
31,
|---------------------------- |  | ----------------------------
|                             |  | 2012                        
|Purchased
    technology     |  | $                           
|Trademarks                   |  |                             
|Non-compete
      agreements |  |                             
|Customer lists               |  |                             
|                             |  | $                           

18

---



The following tables provide a summary of
the carrying value of amortizable intangible assets (in thousands):

|                             |  | As of March 31,
|---------------------------- |  | ---------------
|                             |  | 2012           
|                             |  | GrossAmount    
|Purchased
    technology     |  | $              
|Trademarks                   |  |                
|Non-compete
      agreements |  |                
|Customer lists               |  |                
|                             |  | $              

The total expected future amortization
related to intangible assets is provided in the table below (in thousands):

|                                 | Amortization
|-------------------------------- | ------------
|Fiscal 2013                      | $           
|Fiscal 2014                      |             
|Fiscal 2015                      |             
|Fiscal 2016                      |             
|Total as of March 31,
      2012 | $           

We did not have impairment indicators for
our long-lived assets in fiscal 2012, fiscal 2011 and fiscal 2010. In fiscal
2012, we wrote off $30.9 million of fully amortized intangible assets related to
fiscal 2002 and 2003 acquisitions.

Goodwill

The following provides a summary of the
carrying value of goodwill (in thousands):

|                            |  | Goodwill |         | AccumulatedImpairment Losses |   | Net
      Amount
|--------------------------- |  | -------- | ------- | ---------------------------- | - | ----------------
|Balance March 31, 2010      |  | $        | 385,770 |                              | $ | (339,000        
|Fiscal 2011
      activity  |  |          |        |                              |   |                
|Balance March 31, 2011      |  |          | 385,770 |                              |   | (339,000        
|Pancetera
      acquisition |  |          | 8,843   |                              |   |                
|Balance March 31, 2012      |  | $        | 394,613 |                              | $ | (339,000        

Our annual impairment evaluation for
goodwill in the fourth quarter of fiscal 2012 and fiscal 2011 did not indicate
any impairment of our goodwill for fiscal 2012 or fiscal 2011.

NOTE 6: ACCRUED WARRANTY

The following table details the change in
the accrued warranty balance (in thousands):

|                                                              |  | For the year ended March 31,
|------------------------------------------------------------- |  | ----------------------------
|                                                              |  | 2012                        
|Beginning
balance                                             |  | $                           
|Additional warranties
issued                                  |  |                             
|Adjustments for warranties
      issued in prior fiscal years |  |                             
|Settlements                                                   |  |                             
|Ending balance                                                |  | $                           

19

---



We warrant our products against defects
for 1 to 3 years. A provision for estimated future costs and estimated returns
for credit relating to warranty is recorded when products are shipped and
revenue recognized. Our estimate of future costs to satisfy warranty obligations
is primarily based on historical trends and, if believed to be significantly
different from historical trends, estimates of future failure rates and future
costs of repair. Future costs of repair include materials consumed in the
repair, labor and overhead amounts necessary to perform the repair. If future
actual failure rates differ from our estimates, we record the impact in
subsequent periods. If future actual costs of repair were to differ
significantly from our estimates, we would record the impact of these unforeseen
cost differences in subsequent periods.

NOTE 7: LONG-TERM DEBT AND CONVERTIBLE
SUBORDINATED DEBT

Our debt consisted of the following (in
thousands):

|                                    | As of March 31,
|----------------------------------- | ---------------
|                                    | 2012           
|Senior secured revolving
      debt | $              
|Senior secured term debt            |                
|Convertible subordinated
      debt |                
|                                    | $              

Long-Term Debt

Wells Fargo Credit
Agreement

On March 29, 2012, we refinanced the
senior secured credit agreement with Credit Suisse (CS credit agreement) by
entering into a senior secured credit agreement with Wells Fargo Capital
Finance, LLC (Wells Fargo) providing a revolving credit facility up to $75
million (WF credit agreement). The WF credit agreement matures March 29, 2017,
or August 16, 2015 if our convertible subordinated notes remain outstanding on
that date. We borrowed $49.5 million on March 29, 2012 to repay all borrowings
under the CS credit agreement. Amounts borrowed are included in long-term debt
on the Consolidated Balance Sheets. We incurred and capitalized $1.0 million of
fees related to the WF credit agreement which are included in other long-term
assets in our Consolidated Balance Sheets. These fees are being amortized to
interest expense over the term of the WF credit agreement.

Under the WF credit agreement, we may
borrow on a revolving basis amounts to be used to refinance all debts under our
CS credit agreement as well as for general purposes. The maximum principal
amount that may be borrowed is the lesser of $75 million, reduced by $1.0
million per quarter commencing July 1, 2012, or the amount of the monthly
borrowing base. The monthly borrowing base is comprised of a cash component, an
accounts receivable component and an inventory component. We may prepay all or a
portion of any amounts borrowed without penalty or premium.

The interest rate on amounts borrowed is
based on an election by us of an annual rate equal to (1) a base rate
established by Wells Fargo plus an applicable margin of 1.0% to 1.5%, based on
availability levels under the WF credit agreement or (2) the LIBOR rate plus an
applicable margin ranging from 2.0% and 2.5%, based on availability levels under
the WF credit agreement.

At March 31, 2012, we had $49.5 million
outstanding borrowings at an interest rate of 4.50%, and subsequently elected
the LIBOR rate plus applicable margin on April 5, 2012, bringing the interest
rate to 2.72%. In addition, we have letters of credit totaling $0.1 million,
reducing the amounts available to borrow on the revolver to $25.4 million at
March 31, 2012. Quarterly, we are required to pay a 0.375% commitment fee on
undrawn amounts under the revolving credit facility.

The WF credit agreement contains customary
covenants, including cross-default provisions, as well as financial covenants
that require the fixed charge coverage ratio to be greater than 1.20 for the 12
month period ending on the last day of any month and average liquidity for the
most recently completed month of at least $15 million during the period
commencing on March 29, 2012 and ending on September 30, 2012, increasing to $20
million on October 1, 2012. In addition, to avoid triggering mandatory field
audits and Wells Fargo controlling our cash receipts, we must maintain average
liquidity of at least $20 million during the period commencing on March 29, 2012
and ending on September 30, 2012, increasing to $25 million on October 1, 2012.
Both the fixed charge coverage ratio and average liquidity are defined in the WF
credit agreement. There is also a blanket lien on all of our assets under a
security agreement with Wells Fargo. As of March 31, 2012, we were in compliance
with all covenants.

20

---



Credit Suisse Credit
Agreement

On July 12, 2007, we refinanced a prior
credit facility by entering into a senior secured credit agreement with Credit
Suisse providing a $50 million revolving credit facility and a $400 million
senior secured term loan. We borrowed $400 million on the term loan to repay all
borrowings under a prior credit facility used to fund the Advanced Digital
Information Corporation acquisition. We incurred and capitalized $8.1 million of
loan fees related to the CS credit agreement which were included in other
long-term assets in our Consolidated Balance Sheets. These fees were amortized
to interest expense over the respective loan terms. Interest accrued on the term
loan at our option based on either, a prime rate plus a margin of 2.5%, or a
LIBOR rate plus a margin of 3.5%. During fiscal 2011, we made principal
payments of $81.7 million on the CS credit agreement term loan, and in fiscal
2012 we made principal payments of $104.3 million to fully extinguish the term
loan and CS credit agreement.

Subordinated Term Loans

On November 15, 2010, we paid $121.7
million plus $1.8 million in accrued and unpaid interest to settle subordinated
term loans with EMC International Company. As a result of the voluntary
prepayment in full of these term loans, we have satisfied all of our obligations
under these loans. We funded this payment using proceeds from the 3.50%
convertible subordinated notes.

Convertible Subordinated Debt

Current Notes Issued November
2010

On November 15, 2010, we issued $135
million aggregate principal amount of the current notes due November 15, 2015
(current notes) with a conversion price of $4.33 per share of our common
stock. We may not redeem the notes prior to their maturity date although
investors may convert the current notes into Quantum common stock until November
14, 2015 at their option. In addition, since purchasers are qualified
institutional investors, as defined in Rule 144 under the Securities Act of 1933
(Securities Act), the current notes have not been registered under the
Securities Act. We pay 3.50% interest per annum on the principal amount of the
current notes semi-annually on May 15 and November 15 of each year. The terms of
the current notes are governed by an agreement dated November 15, 2010 between
Quantum and U.S. Bank National Association. The current notes are subordinated
to any existing indebtedness and other liabilities.

We incurred and capitalized $5.0 million
of loan fees in fiscal 2011 for the current notes which are included in other
long-term assets in our Consolidated Balance Sheets. These fees are amortized to
interest expense over the loan term.

4.375% Notes Issued July
2003

On July 30, 2010, we paid $22.1 million
plus $0.5 million in accrued and unpaid interest to redeem the 4.375%
convertible subordinated notes outstanding at that date in accordance with the
contractual terms at maturity. These notes matured August 1,
2010.

Gain (Loss) on Debt Extinguishment, Net
of Costs

In fiscal 2012, in connection with fully
extinguishing the CS term loan and credit agreement on March 29, 2012, we wrote
off $2.3 million of unamortized debt costs related to the CS term loan and
credit agreement.

In fiscal 2011, in connection with the
repayment of our subordinated term loans on November 15, 2010, we wrote off $1.2
million of unamortized debt costs related to these term loans.

In fiscal 2010, in connection with a
tender offer and a private transaction for the 4.375% convertible subordinated
notes issued July 2003, we recorded a gain on debt extinguishment, net of costs,
of $12.9 million comprised of a gross gain of $15.6 million, reduced by $2.1
million in expenses and $0.6 million of unamortized debt costs related to these
notes.

21

---



Debt Maturities

A summary of the scheduled maturities for
our outstanding debt as of March 31, 2012 follows (in thousands):

|                                 | Debt Maturity
|-------------------------------- | -------------
|Fiscal 2013 to fiscal
      2015 | $            
|Fiscal 2016                      |              
|Fiscal 2017                      |              
|Total
      as of March 31, 2012 | $            

Derivatives

We do not engage in hedging activity for
speculative or trading purposes. Under the terms of the CS credit agreement, we
were required to hedge floating interest rate exposure on 50% of our funded debt
balance through December 31, 2009. We entered into an interest rate collar
instrument with a financial institution that fixed the interest rate on $100.0
million of our variable rate term loan from December 31, 2008 through December
31, 2009. We incurred $1.5 million in interest expense in fiscal 2010 on this
collar.

Our interest rate collar did not meet all
of the criteria necessary for hedge accounting. We recorded the fair market
value in other accrued liabilities in the Consolidated Balance Sheets and the
change in fair market value in other income and expense in the Consolidated
Statements of Operations, recognizing a gain of $1.2 million in fiscal 2010. As
of December 31, 2009, the interest rate collar had expired.

NOTE 8: RESTRUCTURING
CHARGES

Our restructuring actions are steps
undertaken to reduce costs in an effort to return to consistent profitability.
In fiscal 2012 and 2011, restructuring actions to consolidate operations
supporting our business were the result of strategic management decisions. In
fiscal 2010, restructuring actions to consolidate operations supporting our
business were undertaken to improve operational efficiencies and to adapt our
operations in recognition of economic conditions. The following summarizes the
type of restructuring expense for fiscal 2012, 2011 and 2010 (in
thousands):

|                             | For the year ended March 31,
|---------------------------- | ----------------------------
|                             | 2012                        
|Severance and
      benefits | $                           
|Facilities                   |                             
|Other                        |                             
|                             | $                           

Fiscal 2012

Restructuring charges in fiscal 2012 were
primarily due to severance and benefits expenses of $1.6 million as a result of
strategic management decisions to consolidate operations supporting our
business. Most areas of the business, including international operations, were
impacted by these restructuring actions. The employees impacted were in our
research and development, sales and marketing and service teams. Facility
restructuring charges for fiscal 2012 were primarily due to negotiating a lease
settlement on a facility vacated in India. The other restructuring reversal for
fiscal 2012 was due to actual payments lower than estimated on a supplier
relationship exited in fiscal 2011.

Fiscal 2011

Restructuring charges in fiscal 2011 were
primarily due to severance and benefits expenses of $3.6 million as a result of
strategic management decisions to consolidate operations supporting our
business. Most areas of the business, including international operations, were
impacted by these restructuring actions. The employees impacted were in our
management, sales and marketing, research and development and service teams. The
facility reversals in fiscal 2011 were primarily due to negotiating settlements
for lease liabilities on two vacated facilities in the U.S. for amounts lower
than the outstanding lease contracts. The other restructuring charges were costs
from exiting a supplier relationship in fiscal 2011.

22

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Fiscal 2010

For fiscal 2010, restructuring charges
were primarily due to $4.8 million in remaining contractual lease payments for
facilities vacated in the U.S. during fiscal 2010. We also vacated a facility in
India and negotiated a settlement for an amount lower than the outstanding lease
contract. Severance and benefits restructuring charges for fiscal 2010 were due
largely to eliminating additional positions in the U.S. and changes in our
estimates, primarily in Europe, as we completed settlement negotiations with
various local authorities. The other restructuring reversal in fiscal 2010 was
due to negotiating a settlement for contract termination fees related to a
program cancelled in a prior year.

The following tables show the activity and
the estimated timing of future payouts for accrued restructuring (in thousands):

|                                          | Severance andbenefits |        | Facilities |  | Other |        | Total
|----------------------------------------- | --------------------- | ------ | ---------- |  | ----- | ------ | -----
|Balance as of March 31,
      2009        | $                     | 3,454  |            |  | $     | 628    |      
|Restructuring costs                       |                       | 1,182  |            |  |       | 5,047  |      
|Restructuring charge
      reversal       |                       | (580   | )          |  |       | (255   | )    
|Cash
      payments                       |                       | (3,597 | )          |  |       | (2,124 | )    
|Non-cash charges and
      other          |                       | 35     |            |  |       | 5      |      
|Balance as of March 31, 2010              |                       | 494    |            |  |       | 3,301  |      
|Restructuring
      costs                 |                       | 3,586  |            |  |       | 307    |      
|Restructuring charge reversal             |                       | (6     | )          |  |       | (845   | )    
|Cash payments                             |                       | (1,189 | )          |  |       | (1,920 | )    
|Non-cash charges and other                |                       |       |            |  |       |       |      
|Balance as of March 31,
      2011        |                       | 2,885  |            |  |       | 843    |      
|Restructuring costs                       |                       | 1,864  |            |  |       | 345    |      
|Restructuring charge
      reversal       |                       | (279   | )          |  |       |       |      
|Cash
      payments                       |                       | (3,181 | )          |  |       | (748   | )    
|Assumed restructuring
      liability     |                       | 23     |            |  |       |       |      
|Balance as of March 31, 2012              | $                     | 1,312  |            |  | $     | 440    |      
|Estimated timing of future
      payouts: |                       |        |            |  |       |        |      
|Fiscal
      2013                         | $                     | 1,312  |            |  | $     | 297    |      
|Fiscal 2014 to
      2016                 |                       |       |            |  |       | 143    |      
|                                          | $                     | 1,312  |            |  | $     | 440    |      

The $1.8 million restructuring accrual as
of March 31, 2012 is primarily comprised of severance and benefits obligations,
the majority of which will be paid in fiscal 2013. The amounts accrued for
vacant facilities will be paid over their respective lease terms, which continue
through fiscal 2016.

Additional charges may be incurred in the
future related to these restructurings, particularly if the actual costs
associated with restructured activities are higher than estimated. Until we
achieve sustained profitability, we may incur additional charges in the future
related to additional cost reduction steps. Future charges that we may incur
associated with future cost reductions are not estimable at this
time.

NOTE 9: STOCK INCENTIVE PLANS AND
SHARE-BASED COMPENSATION

Description of Stock Incentive Plans

Active Stock Incentive
Plans

We have a Long-Term Incentive Plan that
provides for the issuance of stock options, stock appreciation rights, stock
purchase rights and long-term performance awards to our employees, officers, and
consultants, as well as a Nonemployee Director Equity Incentive Plan that
provides for the issuance of stock options, stock appreciation rights, stock
purchase rights and long-term performance awards to our nonemployee directors,
collectively the Active Plans. These plans have authorized 79.5 million shares
of stock of which 7.3 million shares of stock were available for grant as of
March 31, 2012.

23

---



There are 26.5 million stock options and
restricted shares outstanding under the Active Plans as of March 31, 2012, which
expire at various times through June 2018.

With the exception of fiscal 2010, in
recent years we have primarily granted restricted stock units with a zero
purchase price. We continue to grant stock options to employees in certain
circumstances. In fiscal 2010, due to a combination of factors including our
share price at the beginning of the fiscal year, we primarily granted stock
options to our employees. Stock options granted in fiscal 2012, 2011 and 2010
generally vest over three to four years and have contractual terms of seven
years. Grants prior to fiscal 2005 had contractual terms of ten years. Stock
options under the Active Plans are granted at prices determined by the Board of
Directors, but at not less than the fair market value. The majority of
restricted stock units granted to employees in fiscal 2012, 2011 and 2010 vest
over two to three years. Stock option and restricted stock grants to nonemployee
directors typically vest over one year. Both stock options and restricted stock
units granted under the Active Plans are subject to forfeiture if employment
terminates.

Other Stock Option
Plans

During the first quarter of fiscal 2012,
we assumed outstanding unvested options and unvested restricted shares of Pancetera which were exchanged into
options and restricted shares of Quantum common stock, respectively, in
accordance with the merger agreement. As of June 13, 2011, Pancetera had
approximately 0.8 million unvested stock options and 0.5 million unvested
restricted shares outstanding. Based on the exchange ratio of 0.2403 calculated
in accordance with the formula in the merger agreement, we assumed the
outstanding unvested options, which are exercisable for an aggregate of 194,000
shares of Quantum common stock. Based on the relative cash and stock
consideration for Pancetera shares per the merger agreement, the unvested
restricted shares became 33,000 unvested restricted shares of Quantum common
stock and $200,000 in cash held in escrow. The estimated fair value of unvested
Pancetera options, unvested restricted shares and cash held in escrow related to
future service is being recognized over the remaining service
period.

In addition to the Active Plans, we have
other stock option plans, including plans assumed in acquisitions, (Other
Plans) under which stock options, stock appreciation rights, stock purchase
rights, restricted stock awards and long-term performance awards to employees,
consultants, officers and affiliates were authorized. Stock options granted and
assumed under the Other Plans generally vested over one to four years and
expired ten years after the grant date and restricted stock granted under the
Other Plans generally vested over one to three years. The Other Plans have been
terminated and outstanding stock options granted and assumed remain outstanding
and continue to be governed by the terms and conditions of the respective other
stock option plan. Stock options and restricted stock granted under the Other
Plans are subject to forfeiture if employment terminates. Stock options under
the Other Plans were granted at prices determined by the Board of Directors, but
at not less than the fair market value and stock options assumed were governed
by the acquisition agreement. Stock options expire at various times through June
2021.

Stock Purchase Plan

We have an employee stock purchase plan
(the Purchase Plan) that allows for the purchase of stock at 85% of fair
market value at the date of grant or the exercise date, whichever value is less.
The Purchase Plan is qualified under Section 423 of the Internal Revenue Code.
Under the Purchase Plan, rights to purchase shares are granted during the second
and fourth quarter of each fiscal year. Due to cancellation of rights from
August 2008 through January 2010 by the Board of Directors, there were no rights to
purchase shares granted during this period. Rights to purchase shares were
reinstated in February 2010 or the fourth quarter of fiscal 2010. The Purchase
Plan allows a maximum amount of two million shares to be purchased in any one
six month offering period. Employees purchased 3.0 million shares and 3.2
million shares of common stock under the Purchase Plan in fiscal 2012 and 2011,
respectively. The weighted-average price of stock purchased under the Purchase
Plan was $1.66 and $1.22 in fiscal 2012 and 2011, respectively. There were 2.9
million shares available for issuance as of March 31, 2012.

Determining Fair Value

We use the Black-Scholes stock option
valuation model for estimating fair value of stock options granted under our
plans and rights to acquire stock granted under our Purchase Plan. We amortize
the fair value of stock options on a ratable basis over the requisite service
periods, which are generally the vesting periods. The expected life of awards
granted represents the period of time that they are expected to be outstanding.
We determine the expected life based on historical experience with similar
awards, giving consideration to the contractual terms, exercise patterns and
post-vesting forfeitures. We estimate volatility based on the historical
volatility of our common stock over the most recent period corresponding with
the estimated expected life of the award. We base the risk-free interest rate
used in the Black-Scholes stock option valuation model on the implied yield
currently available on U.S. Treasury zero-coupon issues with an equivalent term
equal to the expected life of the award. We have not paid any cash dividends on
our common stock and do not anticipate paying any cash dividends in the foreseeable future. We use historical data to estimate forfeitures and record share-based compensation for those awards that are expected to vest. We adjust share-based compensation for actual forfeitures.

24

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Stock Options

The weighted-average estimated fair
values and the assumptions used in calculating fair values for stock options
granted under the Active Plans during each fiscal period are as follows:

|                                           | For the year ended March 31,
|------------------------------------------ | ----------------------------
|                                           | 2012                        
|Stock option life (in
      years)         |                             
|Risk-free interest rate                    |                             
|Stock price
      volatility               |                             
|Weighted-average grant date fair
    value | $                           

The weighted-average fair value of
stock options assumed from Pancetera, as well as the weighted-average
assumptions used in calculating these values were based on estimates at the
acquisition date as follows:

| | Option life (in
      years) |   | 5.2    |  
| | ---------------------------- | - | ------ | -
| | Risk-free interest rate      |   | 1.65   | %
| | Stock price
      volatility |   | 100.93 | %
| | Weighted-average fair value  | $ | 2.67   |  

The assumed options have a 10 year
contractual life from the original grant date.

Restricted Stock

The fair value of our restricted stock
is the intrinsic value as of the grant date.

Stock Purchase Plan

The weighted-average fair values and
the assumptions used in calculating fair values during each fiscal period are as
follows:

|                                           | For the year ended March 31,
|------------------------------------------ | ----------------------------
|                                           | 2012                        
|Option life (in
      years)               |                             
|Risk-free interest rate                    |                             
|Stock price
      volatility               |                             
|Weighted-average grant date fair
    value | $                           

Share-Based Compensation
Expense

The following tables summarize
share-based compensation expense (in thousands):

|                                                               | For the year ended March 31,
|-------------------------------------------------------------- | ----------------------------
|                                                               | 2012                        
|Share-based compensation
      expense included in operations: |                             
|Cost of
      revenue                                          | $                           
|Research and
      development                                 |                             
|Sales
      and marketing                                      |                             
|General and
      administrative                               |                             
|Total share-based compensation
    expense                     | $                           

|                                                 | For the year ended March
31,
|------------------------------------------------ | ----------------------------
|                                                 | 2012                        
|Share-based compensation
      by type of award: |                             
|Stock
      options                              | $                           
|Restricted
      stock                           |                             
|Stock
      purchase plan                        |                             
|Total share-based
      compensation expense     | $                           

25

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The total share-based compensation cost
capitalized as part of inventory as of March 31, 2012 and 2011 was not material.
During fiscal 2012, 2011 and 2010, no tax benefit was realized for the tax
deduction from stock option exercises and other awards due to tax benefit
carryforwards and tax ordering requirements.

As of March
31, 2012, there was $3.0 million of total unrecognized compensation cost related
to stock options granted under our plans. This unrecognized compensation cost is
expected to be recognized over a weighted-average period of 1.5 years. Total
intrinsic value of stock options exercised for the years ended March 31, 2012,
2011 and 2010 was $3.7 million, $8.9 million and $1.9 million, respectively. We
settle stock option exercises by issuing additional common shares.

As of March 31, 2012, there was $20.8
million of total unrecognized compensation cost related to nonvested restricted
stock. The unrecognized compensation cost for restricted stock is expected to be
recognized over a weighted-average period of 1.9 years. Total fair value of
awards released during the years ended March 31, 2012, 2011 and 2010 was $9.4
million, $7.5 million and $3.1 million, respectively, based on the fair value of
our common stock on the date of award release. We issue additional common shares
upon vesting of restricted stock units.

Stock Activity

Stock Options

A summary of activity relating to all of
our stock option plans is as follows (stock options and intrinsic value in
thousands):

|                                                    | Stock Options |   | Weighted-AverageExercise
      Price |   | Weighted-AverageRemainingContractual
      Term |  | AggregateIntrinsic
Value
|--------------------------------------------------- | ------------- | - | ------------------------------------ | - | ----------------------------------------------- |  | ------------------------
|Outstanding as of March
      31, 2009              | 25,626        |   |                                      | $ | 3.02                                            |  |                         
|Granted                                             | 9,655         |   |                                      |   | 1.01                                            |  |                         
|Exercised                                           | (1,883        | ) |                                      |   | 1.51                                            |  |                         
|Forfeited                                           | (1,778        | ) |                                      |   | 3.32                                            |  |                         
|Expired                                             | (291          | ) |                                      |   | 11.08                                           |  |                         
|Outstanding as of March 31, 2010                    | 31,329        |   |                                      |   | 2.40                                            |  |                         
|Granted                                             | 204           |   |                                      |   | 2.66                                            |  |                         
|Exercised                                           | (6,634        | ) |                                      |   | 1.90                                            |  |                         
|Forfeited                                           | (1,747        | ) |                                      |   | 2.05                                            |  |                         
|Expired                                             | (1,072        | ) |                                      |   | 5.56                                            |  |                         
|Outstanding as of March 31, 2011                    | 22,080        |   |                                      |   | 2.43                                            |  |                         
|Granted and
      assumed                           | 1,619         |   |                                      |   | 2.33                                            |  |                         
|Exercised                                           | (2,982        | ) |                                      |   | 1.79                                            |  |                         
|Forfeited                                           | (619          | ) |                                      |   | 1.90                                            |  |                         
|Expired                                             | (704          | ) |                                      |   | 8.25                                            |  |                         
|Outstanding as of March
      31, 2012              | 19,394        |   |                                      | $ | 2.32                                            |  | 2.72                    
|Vested and expected to vest at March 31,
      2012 | 19,215        |   |                                      | $ | 2.32                                            |  | 2.69                    
|Exercisable as of March
      31, 2012              | 15,963        |   |                                      | $ | 2.46                                            |  | 2.21                    

26

---



The following table summarizes
information about stock options outstanding and exercisable as of March 31, 2012
(stock options in thousands):

|Range of Exercise Prices |      | Stock OptionsOutstanding |   | Weighted-AverageExercisePrice |  | Weighted-AverageRemainingContractual
      Life(Years) |  | Stock OptionsExercisable |      | Weighted-AverageExercisePrice
|------------------------ | ---- | ------------------------ | - | ----------------------------- |  | ------------------------------------------------------ |  | ------------------------ | ---- | -----------------------------
|$                        | 0.11 | -                        | $ | 0.63                          |  | 213                                                    |  | $                        | 0.52 |                              
|$                        | 0.77 | -                        | $ | 0.98                          |  | 5,094                                                  |  |                          | 0.98 |                              
|$                        | 1.00 | -                        | $ | 1.42                          |  | 690                                                    |  |                          | 1.23 |                              
|$                        | 1.52 | -                        | $ | 2.21                          |  | 4,579                                                  |  |                          | 2.02 |                              
|$                        | 2.29 | -                        | $ | 3.42                          |  | 5,850                                                  |  |                          | 2.91 |                              
|$                        | 3.43 | -                        | $ | 4.55                          |  | 2,443                                                  |  |                          | 3.79 |                              
|$                        | 6.70 | -                        | $ | 7.50                          |  | 525                                                    |  |                          | 6.73 |                              
|                         |      |                          |   |                               |  | 19,394                                                 |  | $                        | 2.32 |                              

Expiration dates ranged from April 2012
to June 2021 for stock options outstanding at March 31, 2012. Prices for stock
options exercised during the three-year period ended March 31, 2012, ranged from
$0.11 to $3.86.

Restricted Stock

A summary of activity relating to our
restricted stock follows (shares in thousands):

|                                  | Shares |   | Weighted-AverageGrant DateFair
      Value
|--------------------------------- | ------ | - | ------------------------------------------
|Nonvested at March 31,
      2009 | 6,258  |   |                                           
|Granted                           | 2,526  |   |                                           
|Vested                            | (2,853 | ) |                                           
|Forfeited                         | (796   | ) |                                           
|Nonvested at March 31,
      2010 | 5,135  |   |                                           
|Granted                           | 5,757  |   |                                           
|Vested                            | (3,665 | ) |                                           
|Forfeited                         | (587   | ) |                                           
|Nonvested at March 31,
      2011 | 6,640  |   |                                           
|Granted
      and assumed         | 6,669  |   |                                           
|Vested                            | (3,058 | ) |                                           
|Forfeited                         | (1,390 | ) |                                           
|Nonvested at March 31,
      2012 | 8,861  |   |                                           

NOTE 10: 401K PLAN

Substantially all of the U.S. employees
are eligible to make contributions to our 401(k) savings and investment plan. We
typically make discretionary contributions to the plan by matching a percentage
of our employees contributions. Employer contributions were $3.0 million, $2.6
million and $2.5 million in fiscal 2012, 2011 and 2010, respectively.

NOTE 11: INCOME TAXES

Pre-tax income (loss) reflected in the
Consolidated Statements of Operations for the years ended March 31, 2012, 2011
and 2010 follows (in thousands):

|        | For the year ended March
31,
|------- | ----------------------------
|        | 2012                        
|U.S     | $                           
|Foreign |                             
|        | $                           

27

---



Income tax provision consists of the
following (in thousands):

|                         | For the year ended March
31,
|------------------------ | ----------------------------
|                         | 2012                        
|Federal:                 |                             
|Current                  | $                           
|Deferred                 |                             
|                         |                             
|State:                   |                             
|Current                  |                             
|Deferred                 |                             
|                         |                             
|Foreign:                 |                             
|Current                  |                             
|Deferred                 |                             
|                         |                             
|Income tax
    provision | $                           

The income tax provision differs from
the amount computed by applying the federal statutory rate of 35% to income
(loss) before income taxes as follows (in thousands):

|                                                       | For the year ended March 31,
|------------------------------------------------------ | ----------------------------
|                                                       | 2012                        
|Expense (benefit) at
      federal statutory rate      | $                           
|State taxes                                            |                             
|Unbenefited losses and
      credits                   |                             
|Net accrual (release) of contingent tax
      reserves |                             
|Other                                                  |                             
|                                                       | $                           

Significant components of deferred tax
assets and liabilities are as follows (in thousands):

|                                                                            | As of March 31,
|--------------------------------------------------------------------------- | ---------------
|                                                                            | 2012           
|Deferred tax
    assets:                                                    |                
|Inventory valuation method                                                  | $              
|Accrued warranty
      expense                                              |                
|Distribution reserves                                                       |                
|Loss
      carryforwards                                                    |                
|Foreign
      tax and research and development credit carryforwards         |                
|Restructuring charge
      accruals                                         |                
|Other
      accruals and reserves not currently deductible for tax purposes |                
|Depreciation and
      amortization methods                                 |                
|                                                                            |                
|Less valuation
      allowance                                              |                
|Deferred tax asset                                                          | $              
|Deferred tax
      liabilities:                                             |                
|Acquired intangibles                                                        | $              
|Tax on unremitted
      foreign earnings                                    |                
|Other                                                                       |                
|Deferred tax
      liability                                                | $              
|Net deferred tax asset (liability)                                          | $              

28

---



A reconciliation of the gross unrecognized
tax benefits follows (in thousands):

|                                                                                                                    | For the year ended March
      31,
|------------------------------------------------------------------------------------------------------------------- | ----------------------------------
|                                                                                                                    | 2012                              
|Beginning balance                                                                                                   | $                                 
|Settlement and effective
      settlements with tax authorities and
      related             
      remeasurements |                                   
|Lapse of statute of
      limitations                                                                               |                                   
|Increase in balances related
      to tax positions taken in prior period                                           |                                   
|Increases in balances related
      to tax positions taken during current period                                    |                                   
|Ending balance                                                                                                      | $                                 

During fiscal 2012, we recorded a net
decrease in our unrecognized tax benefits. Including interest and penalties, the
total unrecognized tax benefit at March 31, 2012 was $33.6 million, all of
which, if recognized, would favorably affect the effective tax rate. At March
31, 2012 accrued interest and penalties totaled $0.9 million.

We file our tax returns as prescribed by
the laws of the jurisdictions in which we operate. Our U.S. tax returns have
been audited for years through 2002 by the Internal Revenue Service. In other
major jurisdictions, we are generally open to examination for the most recent
three to five fiscal years. Although timing of the resolution and closure on
audits is highly uncertain, we do not believe it is likely that the unrecognized
tax benefits would materially change in the next 12 months.

As of March 31, 2012, we had federal net
operating loss and tax credit carryforwards of approximately $202.7 million and
$156.9 million, respectively. Our federal net operating loss carryforwards
include $33.6 million attributable to excess tax deductions from stock option
exercises, and are not included in the deferred tax assets shown above. The
benefit of these loss carryforwards will be credited to equity when realized.
The net operating loss and tax credit carryforwards expire in varying amounts
beginning in fiscal 2013 if not previously utilized, the utilization of which is
limited under the tax law ownership change provision. These carryforwards
include $10.8 million of acquired net operating losses and $15.6 million of
credits.

Certain changes in stock ownership could
result in a limitation on the amount of net operating loss and tax credit
carryovers that can be utilized each year. Should the company undergo such a
change in stock ownership, it could severely limit the usage of these carryover
tax attributes against future income, resulting in additional tax charges.

Due to our history of net losses and the
difficulty in predicting future results, we believe that we cannot rely on
projections of future taxable income to realize the deferred tax assets.
Accordingly, we have established a full valuation allowance against our U.S. net
deferred tax assets. Significant management judgment is required in determining
our deferred tax assets and liabilities and valuation allowances for purposes of
assessing our ability to realize any future benefit from our net deferred tax
assets. We intend to maintain this valuation allowance until sufficient positive
evidence exists to support the reversal of the valuation allowance. Our income
tax expense recorded in the future will be reduced to the extent that sufficient
positive evidence materializes to support a reversal of, or decrease in, our
valuation allowance.

NOTE 12: NET INCOME (LOSS) PER
SHARE

Equity Instruments Outstanding

We have granted stock options and
restricted stock units under our Plans that, upon exercise and vesting,
respectively, would increase shares outstanding. On November 15, 2010, we issued
3.50% convertible subordinated notes which are convertible at the option of the
holders at any time prior to maturity into shares of Quantum common stock at a
conversion price of $4.33 per share. These notes, if converted, would increase
shares outstanding.

On June 3, 2009 we entered into an
agreement with EMC Corporation (EMC) which provides for the issuance of
certain warrants. On June 23, 2009, we issued a warrant to EMC to purchase 10
million shares of our common stock at a $0.38 per share exercise price. Only in
the event of a change of control of Quantum will this warrant vest and be
exercisable. It expires seven years from the date of issuance or three years
after change of control, whichever occurs first. Due to these terms, no
share-based compensation expense related to this warrant has been recorded to
date.

29

---



At March 31, 2010, we had outstanding
4.375% convertible subordinated notes which were convertible at the option of
the holders at any time prior to maturity into shares of Quantum common stock at
a conversion price of $4.35 per share.

Net Income (Loss) per Share

The following table set forth the
computation of basic and diluted net income (loss) per share (in thousands,
except per-share data):

|                                                                              | For the year
      ended March 31,
|----------------------------------------------------------------------------- | ----------------------------------
|                                                                              | 2012                              
|Net income (loss)                                                             | $                                 
|Interest on dilutive
      notes                                              |                                   
|Net
      gain on extinguishment of dilutive notes                            |                                   
|Income (loss) for purposes of computing income (loss) per diluted
      share | $                                 
|Weighted average shares and common share
      equivalents (CSE):           |                                   
|Basic                                                                         |                                   
|Dilutive CSE from stock plans                                                 |                                   
|Dilutive CSE from purchase plan                                               |                                   
|Dilutive CSE from convertible notes                                           |                                   
|Diluted                                                                       |                                   
|Basic net income (loss) per share                                             | $                                 
|Diluted net income (loss) per share                                           | $                                 

The computations of diluted net income
(loss) per share for the periods presented excluded the following because the
effect would have been antidilutive:

- For fiscal 2012 and 2011, 31.2 million and 11.6
  million weighted equivalent shares, respectively, of the 3.50% convertible subordinated notes were
excluded.
- Stock options to purchase 11.5 million, 10.4
  million and 18.8 million weighted average shares in fiscal 2012, 2011 and 2010 respectively, were excluded.
- Unvested restricted stock units of 5.1 million,
  49,000 and 0.2 million weighted average shares for fiscal 2012, 2011 and 2012, respectively, were excluded.

NOTE 13: COMMITMENTS AND
CONTINGENCIES

Lease Commitments

We lease certain facilities under
non-cancelable lease agreements and also have equipment leases for various
office equipment. Some of the leases have renewal options ranging from one to
ten years and others contain escalation clauses. These leases are operating
leases.

In February
2006, we leased a campus facility in Colorado Springs, Colorado, comprised of
three buildings in three separate operating leases with initial terms of five,
seven and 15 years. In August 2010, we negotiated lower lease rates and a five
year extension on one of the buildings. The future minimum lease payment
schedule below includes $29.9 million for this Colorado Springs campus.

Rent expense was $12.7 million in both
fiscal 2012 and 2011 and $13.8 million for fiscal 2010. Sublease income was
immaterial in fiscal 2012 and 2011 and was $0.7 million for fiscal 2010.

30

---



Future minimum lease payments are as
follows (in thousands):

|                                    | Lease Payments
|----------------------------------- | --------------
|For the year ending March
      31, |               
|2013                                | $             
|2014                                |               
|2015                                |               
|2016                                |               
|2017                                |               
|Thereafter                          |               
|                                    | $             

Commitments to Purchase Inventory

We use contract manufacturers for certain
manufacturing functions. Under these arrangements, the contract manufacturer
procures inventory to manufacture products based upon our forecast of customer
demand. We are responsible for the financial impact on the contract manufacturer
of any reduction or product mix shift in the forecast relative to materials that
the contract manufacturer had already purchased under a prior forecast. Such a
variance in forecasted demand could require a cash payment for finished goods in
excess of current customer demand or for costs of excess or obsolete inventory.
As of March 31, 2012 and 2011, we had issued non-cancelable purchase commitments
for $34.3 million and $33.8 million, respectively, to purchase finished goods
from our contract manufacturers.

Legal Proceedings

On September 12, 2011, Compression
Technology Solutions LLC (CTS) filed a patent infringement lawsuit against a
group of companies, consisting of Quantum, CA., Inc., EMC Corporation,
Hewlett-Packard Company, International Business Machines Corp., NetApp, Inc. and
Quest Software, Inc., in the U.S. District Court in the Eastern District of
Missouri, alleging that certain unspecified products of the defendants,
characterized as deduplication software systems, and, in the case of Quantum,
including Quantums DXi Series Deduplication software, fall within the scope
of patent 5,414,650. CTS is seeking injunctive relief, as well as the recovery
of monetary damages, including treble damages for willful infringement. We do
not believe we infringe the CTS patent; we believe that the CTS patent is
invalid, and we intend to defend ourselves vigorously. In April 2012, our motion
to transfer venue was granted and the lawsuit was transferred to the U.S.
District Court in the Northern District of California. Due to the inherent
uncertainty of litigation, we cannot identify probable or estimable damages
related to the lawsuit.

Indemnifications

We have certain financial guarantees, both
express and implied, related to product liability and potential infringement of
intellectual property. Other than certain product liabilities recorded as of
March 31, 2012 and 2011, we did not record a liability associated with these
guarantees, as we have little or no history of costs associated with such
indemnification requirements. Contingent liabilities associated with product
liability may be mitigated by insurance coverage that we maintain.

In the normal course of business to
facilitate transactions of our services and products, we indemnify certain
parties with respect to certain matters. We have agreed to hold certain parties
harmless against losses arising from a breach of representations or covenants,
or out of intellectual property infringement or other claims made against
certain parties. These agreements may limit the time within which an
indemnification claim can be made and the amount of the claim. In addition, we
have entered into indemnification agreements with our officers and directors,
and our bylaws contain similar indemnification obligations to our agents.

It is not possible to determine the
maximum potential amount under these indemnification agreements due to the
limited history of our indemnification claims and the unique facts and
circumstances involved in each particular agreement. Historically, payments made
by us under these agreements have not had a material impact on our operating
results, financial position or cash flows.

31

---



NOTE 14: GEOGRAPHIC AND CUSTOMER
INFORMATION

Revenue, attributed to regions based on
the location of customers, and long-lived assets, comprised of property and
equipment, by region were as follows (in thousands):

|             | As of and for the year ended March
      31,
|------------ | --------------------------------------------
|             | 2012                                        
|             | Revenue                                     
|Americas     | $                                           
|Europe       |                                             
|Asia Pacific |                                             
|             | $                                           

No customer accounted for 10% or more of
our revenue in fiscal 2012. Dell accounted for $68.7 million and 10% of revenue
in fiscal 2011 and $86.5 million or 13% of revenue in fiscal 2010.

Following are revenues attributable to
each of our product groups, services and royalties (in
thousands):

|                                          | For the year ended March
31,
|----------------------------------------- | ----------------------------
|                                          | 2012                        
|Disk systems and software
      solutions | $                           
|Tape automation systems                   |                             
|Devices and
media                         |                             
|Service                                   |                             
|Royalty                                   |                             
|Total revenue                             | $                           

NOTE 15: UNAUDITED QUARTERLY FINANCIAL
DATA

|                                                    | For the year ended March 31,
    2012
|--------------------------------------------------- | -------------------------------------
|**(In thousands, except per share
      data)**     | 1stQuarter                           
|Revenue                                             | $                                    
|Gross margin                                        |                                      
|Net income
(loss)                                   |                                      
|Basic and diluted net income (loss) per
      share |                                      

|                                                    | For the year ended March 31,
    2011
|--------------------------------------------------- | -------------------------------------
|                                                    | 1stQuarter                           
|Revenue                                             | $                                    
|Gross margin                                        |                                      
|Net income
(loss)                                   |                                      
|Basic and diluted net income (loss) per
      share |                                      

32

---



SCHEDULE II

CONSOLIDATED VALUATION AND QUALIFYING
ACCOUNTS

|Allowance for doubtful accounts (in thousands):
|-----------------------------------------------
|                                               
|For the year ended:                            
|March 31, 2010                                 
|March 31, 2011                                 
|March 31, 2012                                 

(i)Uncollectible accounts
written off, net of recoveries.

33

---



PART IV

ITEM 15. EXHIBITS, FINANCIAL STATEMENT
SCHEDULES

Upon written request, we will provide,
without charge, a copy of our Annual Report on Form 10-K, including the
Consolidated Financial Statements, financial statement schedules and any
exhibits for our most recent fiscal year. All requests should be sent to:

Investor RelationsQuantum Corporation1650 Technology Drive,
Suite 800San Jose, California 95110(408) 944-4450

| | (a) The following
      documents are filed as a part of this Report:
| | ---------------------------------------------------------------------
| |                                                                      
| | 1.                                                                   
| |                                                                      
| | 2.                                                                   
| |                                                                      
| | (b)Exhibits                                                          

34

---



|              |       |                           |  |                                                                                                                                                                                                                                                                  |  | Incorporated
      by Reference
|------------- | ----- | ------------------------- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | -------------------------------
|ExhibitNumber |       | Exhibit
      Description |  | Form                                                                                                                                                                                                                                                             |  | File No.                       
|              | 2.1   |                           |  | Agreement and Plan of
      Merger by and between Registrant, Pancetera Software, Inc., Quarry
      Acquisition Corporation and Henrik Rosendahl as the stockholder
      representative, dated June 13, 2011.                                                  |  | 10-Q                           
|              | 3.1   |                           |  | Amended and Restated
      Certificate of Incorporation of Registrant.                                                                                                                                                                                           |  | 8-K                            
|              | 3.2   |                           |  | Amended and Restated
      By-laws of Registrant, as amended.                                                                                                                                                                                                    |  | 8-K                            
|              | 3.3   |                           |  | Certificate of
      Designation of Rights, Preferences and Privileges of Series B Junior
      Participating Preferred Stock.                                                                                                                                   |  | S-3                            
|              | 3.4   |                           |  | Certification of
      Amendment to the Bylaws of Quantum Corporation, as adopted on January 20,
      2010.                                                                                                                                                     |  | 8-K                            
|              | 4.1   |                           |  | Stockholder Agreement,
      dated as of October 28, 2002, by and between Registrant and Private
      Capital Management.                                                                                                                                       |  | 10-Q                           
|              | 4.2   |                           |  | Indenture for 3.50% Convertible Senior
      Subordinated Notes due 2015, between the Registrant and U.S. Bank National
      Association, as trustee, dated November 15, 2010, including the form of
      3.50% Convertible Senior Subordinated Note due 2015. |  | 8-K                            
|              | 10.1  |                           |  | Form of Indemnification
      Agreement between Registrant and the Named Executive Officers and
      Directors. *                                                                                                                                               |  | 8-K                            
|              | 10.2  |                           |  | Chief Executive Change
      of Control Agreement between Registrant and Jon W. Gacek.*                                                                                                                                                                          |  | 8-K                            
|              | 10.3  |                           |  | Executive Chairman
      Change of Control Agreement between Registrant and Richard E. Belluzzo.*                                                                                                                                                                |  | 8-K                            
|              | 10.4  |                           |  | Form of Officer Change
      of Control Agreement between Registrant and each of Registrants Executive
      Officers (Other than the Executive Chairman and the CEO).*                                                                                         |  | 8-K                            
|              | 10.5  |                           |  | Form of Amended and
      Restated Director Change of Control Agreement between Registrant and the
      Directors (Other than the Executive Chairman and the CEO).*                                                                                             |  | 8-K                            
|              | 10.6  |                           |  | Amended and Restated
      1993 Long-Term Incentive Plan effective November 10, 2007. *                                                                                                                                                                          |  | 8-K                            
|              | 10.7  |                           |  | Form of Restricted Stock
      Unit Agreement. For U.S. employees under the Amended and Restated 1993
      Long-Term Incentive Plan. *                                                                                                                          |  | 10-Q                           
|              | 10.8  |                           |  | Form of Restricted Stock
      Unit Agreement. For non-U.S. employees under the Amended and Restated 1993
      Long-Term Incentive Plan. *                                                                                                                      |  | 10-Q                           
|              | 10.9  |                           |  | Form of Stock Option
      Agreement. For U.S. employees under the Amended and Restated 1993
      Long-Term Incentive Plan. *                                                                                                                                   |  | 10-K                           
|              | 10.10 |                           |  | Form of Stock Option
      Agreement. For non-U.S. employees under the Amended and Restated 1993
      Long-Term Incentive Plan. *                                                                                                                               |  | 10-K                           
|              | 10.11 |                           |  | Form of Stock Option
      Agreement. For Chief Executive Officer under the Amended and Restated 1993
      Long-Term Incentive Plan. *                                                                                                                          |  | 10-K                           
|              | 10.12 |                           |  | Amended and Restated
      Nonemployee Director Equity Incentive Plan effective November 10, 2007. *                                                                                                                                                             |  | 8-K                            
|              | 10.13 |                           |  | Form of Stock Option
      Agreement under the Amended and Restated Nonemployee Director Equity
      Incentive Plan, effective November 10, 2007. *                                                                                                             |  | 10-K                           

35

---



|              |       |                     |  |                                                                                                                                                                                                       |  | **Incorporated
      by Reference**
|------------- | ----- | ------------------- |  | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | -----------------------------------
|ExhibitNumber |       | Exhibit Description |  | Form                                                                                                                                                                                                  |  | File No.                           
|              | 10.14 |                     |  | Form
      of Restricted Stock Unit Agreement under the Amended and Restated
      Nonemployee Director Equity Incentive Plan, effective November 10, 2007.
      *                                   |  | 10-Q                               
|              | 10.15 |                     |  | Advanced Digital
      Information Corporation Amended and Restated 1999 Stock Incentive
      Compensation Plan. *                                                                                   |  | S-8                                
|              | 10.16 |                     |  | Employment Offer Letter, dated March 31, 2011, between Registrant
      and Jon W. Gacek.*                                                                                                            |  | 8-K                                
|              | 10.17 |                     |  | Offer Letter, dated
      March 31, 2011, between Registrant and Richard E. Belluzzo.*                                                                                                                |  | 8-K                                
|              | 10.18 |                     |  | Employment Offer Letter, dated August 31, 2006, between Registrant
      and William C. Britts. *                                                                                                     |  | 8-K                                
|              | 10.19 |                     |  | Amendment to
      Employment Offer Letter between Registrant and William C. Britts.
    *                                                                                                            |  | 10-Q                               
|              | 10.20 |                     |  | Amendment to Employment Offer Letter between Registrant and William
      C. Britts.*                                                                                                                 |  | 10-Q                               
|              | 10.21 |                     |  | Offer Letter, dated
      May 25, 2007, between Registrant and Joseph A. Marengi. *                                                                                                                   |  | 8-K                                
|              | 10.22 |                     |  | Credit Agreement, dated March 29, 2012, by and among the
      Registrant, Wells Fargo Capital Finance, LLC, as Administrative Agent, and
      the Lenders party thereto.                           |  |                                    
|              | 10.23 |                     |  | Security Agreement,
      dated March 29, 2012, among the Registrant and Wells Fargo Capital
      Finance, LLC.                                                                                      |  | 8-K                                
|              | 10.24 |                     |  | Offer
      Letter of Mr. David A. Krall, dated August 11, 2011.*                                                                                                                                     |  | 8-K                                
|              | 10.25 |                     |  | Offer Letter, dated
      May 2, 2011, between Registrant and David E. Roberson. *                                                                                                                    |  | 8-K                                
|              | 10.26 |                     |  | Agreement for Purchase and Sale of Real Property, dated as November
      18, 2005, among Registrant, SELCO Service Corporation and CS/Federal Drive
      LLC, as amended by Amendments 1 through 6. |  | 8-K                                
|              | 10.27 |                     |  | Lease Agreement,
      dated February 6, 2006, between Registrant and CS/Federal Drive AB LLC
      (for Building A).                                                                                 |  | 8-K                                
|              | 10.28 |                     |  | Lease
      Agreement, dated February 6, 2006, between Registrant and CS/Federal Drive
      AB LLC (for Building B).                                                                                 |  | 8-K                                
|              | 10.29 |                     |  | Lease Agreement,
      dated February 6, 2006, between Registrant and CS/Federal Drive AB LLC
      (for Building C).                                                                                 |  | 8-K                                
|              | 10.30 |                     |  | Patent Cross License Agreement, dated February 27, 2006, between
      Registrant and Storage Technology Corporation.                                                                                 |  | 8-K                                
|              | 10.31 |                     |  | Tax Sharing and
      Indemnity Agreement by and among Registrant, Maxtor Corporation and Insula
      Corporation, dated April 2, 2001.                                                              |  | 8-K                                
|              | 10.32 |                     |  | Mutual General Release and Global Settlement Agreement, dated as of
      December 23, 2004, between Maxtor Corporation and Registrant.                                                               |  | 10-Q                               
|              | 10.33 |                     |  | Offer Letter, dated
      August 20, 2007, between Registrant and Paul Auvil. *                                                                                                                       |  | 8-K                                
|              | 10.34 |                     |  | Warrant Purchase Agreement, dated as of June 3, 2009, by and
      between Quantum Corporation and EMC Corporation.                                                                                   |  | 8-K                                
|              | 10.35 |                     |  | First Amendment to
      the Purchase Agreement, dated as of June 17, 2009, by and between Quantum
      Corporation and EMC Corporation.                                                             |  | 8-K                                
|              | 10.36 |                     |  | Amended and Restated Employee Stock Purchase Plan, dated January 1,
      2010.*                                                                                                                      |  | 8-K                                

36

---



|              |      |                                                              |  |                                                                                                                                                                  |  | Incorporated
      by Reference
|------------- | ---- | ------------------------------------------------------------ |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- |  | -------------------------------
|ExhibitNumber |      | Exhibit
      Description                                    |  | Form                                                                                                                                                             |  | File No.                       
|              | 12.1 |                                                              |  | Ratio of Earnings to Fixed
Charges.                                                                                                                              |  | 10-K                           
|              | 21   |                                                              |  | Quantum Subsidiaries.                                                                                                                                            |  | 10-K                           
|              | 23   |                                                              |  | Consent of Independent Registered Public
      Accounting Firm, PricewaterhouseCoopers LLP.                                                                     |  |                                
|              | 24   |                                                              |  | Power of Attorney (see signature page).                                                                                                                          |  |                                
|              | 31.1 |                                                              |  | Certification of the Chief Executive Officer
      pursuant to Section 302(a) of the Sarbanes-Oxley Act of 2002.                                                |  |                                
|              | 31.2 |                                                              |  | Certification of the Chief Financial Officer pursuant to Section
      302(a) of the Sarbanes-Oxley Act of 2002.                                                |  |                                
|              | 32.1 |                                                              |  | Certification of Chief Executive Officer
      pursuant to 18 U.S.C. section 1350, as adopted pursuant to section 906 of
      the Sarbanes-Oxley act of 2002.  |  |                                
|              | 32.2 |                                                              |  | Certification of Chief Financial Officer pursuant to 18 U.S.C.
      section 1350, as adopted pursuant to section 906 of the Sarbanes-Oxley act
      of 2002.  |  |                                
|101.INS       |      | XBRL Instance Document.                                      |  | 10-K                                                                                                                                                             |  | 001-13449                      
|101.SCH       |      | XBRL Taxonomy Extension Schema Document.                     |  | 10-K                                                                                                                                                             |  | 001-13449                      
|101.CAL       |      | XBRL Taxonomy Extension Calculation Linkbase
      Document. |  | 10-K                                                                                                                                                             |  | 001-13449                      
|101.DEF       |      | XBRL Taxonomy Extension Definition Linkbase Document.        |  | 10-K                                                                                                                                                             |  | 001-13449                      
|101.LAB       |      | XBRL Taxonomy Extension Label Linkbase
      Document.       |  | 10-K                                                                                                                                                             |  | 001-13449                      
|101.PRE       |      | XBRL Taxonomy Extension Presentation Linkbase Document.      |  | 10-K                                                                                                                                                             |  | 001-13449                      

|* |  | Indicates management contract or compensatory plan, contract or
      arrangement.
|- |  | ----------------------------------------------------------------------------------
| |  | Filed herewith.                                                                   
| |  | Furnished herewith.                                                               

37

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SIGNATURE

Pursuant to the requirements of the
Securities Exchange Act of 1934, the registrant has duly caused this report to
be signed on its behalf by the undersigned, thereunto duly authorized.

QUANTUM CORPORATION/s/
      LINDA M. BREARDLinda M. BreardChief Financial Officer(Principal Financial and Chief
      Accounting Officer)


Dated: March 8, 2013

38

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