Exhibit 5.1

                                 June 29, 2001

Quantum Corporation
501 Sycamore
Milpitas, CA 95035

     RE:  REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

     We have examined the Registration Statement on Form S-8 to be filed by you
with the Securities and Exchange Commission on or about July 2, 2001 (the
"Registration Statement"), in connection with the registration under the
Securities Act of 1933, as amended, of 9,842,228 shares of Quantum Corporation--
DSSG Common Stock, par value $0.01 per share (the "Shares"), reserved for
issuance pursuant to the Supplemental  Stock Option Plan, the 1993 Long-Term
Incentive Plan and the 1996 Directors Plan (the "Plans").  As your counsel in
connection with the transaction, we have examined the proceedings taken and are
familiar with the proceedings proposed to be taken by you in connection with the
sale and issuance of the Shares pursuant to the Plans.

     It is our opinion, when issued and sold in the manner referred to in the
Plans, the Shares will be legally and validly issued, fully paid and
nonassessable.

     We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the
Registration Statement and any amendment thereto.

                                    Very truly yours,

                                    /s/ Wilson Sonsini Goodrich & Rosati

                                    WILSON SONSINI GOODRICH & ROSATI
                                    Professional Corporation