Exhibit 99.2

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                       AS ADOPTED PURSUANT TO SECTION 906
                        OF THE SARBANES-OXLEY ACT OF 2002

         In connection with the annual report of Advanced Digital Information
Corporation (the "Company") on Form 10-K for the fiscal year ended October 31,
2002 as filed with the Securities and Exchange Commission on the date hereof
(the "Form 10-K"), I, Jon W. Gacek, Senior Vice President and Chief Financial
Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted
pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

         1. The Form 10-K fully complies with the requirements of Section 13(a)
or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m or 78o(d)); and

         2. The information contained in the Form 10-K fairly presents, in all
material respects, the financial condition and results of operations of the
Company.

Dated: January 28, 2003                    JON W. GACEK
                                           -----------------------------------
                                           Jon W. Gacek, Senior Vice President
                                           and Chief Financial Officer