<TABLE> <S> <C>
<PAGE>
<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
FINANCIAL STATEMENTS OF QUANTUM CORPORATION.
</LEGEND>
<MULTIPLIER> 1,000
<S> <C> <C> <C>
<PERIOD-TYPE> 12-MOS 12-MOS 12-MOS
<FISCAL-YEAR-END> MAR-31-2000 MAR-31-1999 MAR-31-1998
<PERIOD-START> APR-01-1999 APR-01-1998 APR-01-1997
<PERIOD-END> MAR-31-2000 MAR-31-1999 MAR-31-1998
<CASH> 918,262 772,368 642,150
<SECURITIES> 32,080 24,426 71,573
<RECEIVABLES> 632,336 658,687 750,856
<ALLOWANCES> 23,111 12,130 12,928
<INVENTORY> 223,825 271,986 315,035
<CURRENT-ASSETS> 2,013,554 1,927,873 2,025,337
<PP&E> 536,354 563,545 505,640
<DEPRECIATION> 299,669 291,617 220,481
<TOTAL-ASSETS> 2,533,952 2,483,596 2,438,411
<CURRENT-LIABILITIES> 854,247 682,005 700,236
<BONDS> 325,338 344,461 327,485
0 0 0
0 0 0
<COMMON> 737,020 886,434 776,291
<OTHER-SE> 562,011 503,356 595,731
<TOTAL-LIABILITY-AND-EQUITY> 2,533,952 2,483,596 2,438,411
<SALES> 4,727,204 4,902,056 5,805,235
<TOTAL-REVENUES> 4,727,204 4,902,056 5,805,235
<CGS> 3,848,244 4,030,718 4,929,714
<TOTAL-COSTS> 3,848,244 4,030,718 4,929,714
<OTHER-EXPENSES> 802,393 727,099 580,136
<LOSS-PROVISION> 0 0 0
<INTEREST-EXPENSE> 28,385 27,481 32,753
<INCOME-PRETAX> 89,170 (185) 230,815
<INCOME-TAX> 48,326 29,350 60,014
<INCOME-CONTINUING> 40,844 (29,535) 170,801
<DISCONTINUED> 0 0 0
<EXTRAORDINARY> 0 0 0
<CHANGES> 0 0 0
<NET-INCOME> 40,844 (29,535) 170,801
<EPS-BASIC> 0<F1> (0.18) 1.25
<EPS-DILUTED> 0<F2> (0.18) 1.07
<FN>
<F1> From April 1, 1999 through August 3, 1999:
Quantum EPS -- Primary (0.10)
From August 4, 1999 through March 31, 2000:
DSS Group EPS -- Primary 0.53
HDD Group EPS -- Primary (0.33)
<F2> From April 1, 1999 through August 3, 1999:
Quantum EPS -- Diluted (0.10)
From August 4, 1999 through March 31, 2000:
DSS Group EPS -- Diluted 0.51
HDD Group EPS -- Diluted (0.33)
</FN>
</TABLE>