<PAGE>   1
                                                                     EXHIBIT 3.2

                            CERTIFICATE OF AMENDMENT
                                       OF
                AMENDED AND RESTATED CERTIFICATE OF INCORPORATION
                                       OF
                            STORAGE DIMENSIONS, INC.
                             A DELAWARE CORPORATION

         Storage Dimensions, Inc., a corporation organized and existing under
and by virtue of the General Corporation Law of the State of Delaware (the
"Corporation"), does hereby certify as follows:

FIRST:   The name of the Corporation is Storage Dimensions, Inc.

SECOND: The original Certificate of Incorporation of the Corporation was filed
with the Secretary of State of Delaware on November 25, 1992 under the name SDI
Acquisition Corporation.

THIRD: The Board of Directors of the Corporation, acting in accordance with the
provisions of Sections 141 and 242 of the General Corporation Law of the State
of Delaware, adopted resolutions amending its Second Amended and Restated
Certificate of Incorporation as follows:

         ARTICLE I shall be amended and restated to read in its entirety as
follows:

         "The name of the Corporation is Artecon, Inc. (hereinafter sometimes
referred to as the "Corporation")."

         ARTICLE IV shall be amended and restated to read in its entirety as
follows:

"1. The Corporation is authorized to issue a total of Fifty Million (50,000,000)
shares of stock in two classes designated respectively "Preferred Stock" and
"Common Stock." The total number of shares of Preferred Stock the Corporation
shall have authority to issue is Ten Million (10,000,000), par value one-half of
one cent ($.005) per share, and the total number of shares of Common Stock the
Corporation shall have authority to issue is Forty Million (40,000,000), par
value one-half of one cent ($.005) per share.

2. The preferences, privileges and restrictions granted to or imposed on the
respective classes and series of shares of Common Stock and Preferred Stock are
as follows:

         (a) DESIGNATION OF SERIES OF PREFERRED STOCK. The Preferred Stock may
be issued from time to time in one or more series. The Board of Directors is
hereby authorized, within the limitations and restrictions stated in this
Certificate of Incorporation, 



                                       1.
<PAGE>   2

to fix or alter the dividend rights, dividend rate, conversion rights, voting
rights, rights and terms of redemption (including sinking fund provisions), the
redemption price or prices, and the liquidation preferences of any wholly
unissued series of Preferred Stock, and the number of shares constituting any
such series and the designation thereof, or any of them; and to increase or
decrease the number of shares of any series subsequent to the issuance of shares
of that series, but not below the number of shares of such series then
outstanding. In case the number of shares of any series shall be so decreased,
the shares constituting such decrease shall resume the status which they had
prior to the adoption of the resolution originally fixing the number of shares
of such series.

         (b) DESIGNATION OF SERIES A PREFERRED STOCK. Two Million Four Hundred
Ninety-Four Thousand One Hundred Fifty-Nine (2,494,159) of the shares of
Preferred Stock are hereby designated "Series A Preferred Stock" ("Series A
Stock"). The rights, preferences and privileges of the Series A Stock are as
specified in this Section 2 of Article IV.

         (c) DIVIDEND RIGHTS. The holders of record of Preferred Stock and
Common Stock shall be entitled to receive dividends on a non-cumulative basis
when and as declared by the Board of Directors out of funds legally available
therefor. No right shall accrue to the holders of the Series A Stock by reason
of the fact that dividends are not declared and thereafter paid in any year.

         (d)      PREFERENCE ON LIQUIDATION.

                  (i) In the event of any liquidation, dissolution or winding up
of the Corporation, either voluntary or involuntary, the holders of the Series A
Stock shall be entitled to receive, prior and in preference to any distribution
of any of the assets or surplus funds of the Corporation to the holders of the
Common Stock or any other class or series of stock of the Corporation, an amount
equal to two dollars ($2.00) per share (as adjusted for any stock dividends,
combinations or splits, reclassifications or the like with respect to such
shares) plus all accrued, accumulated or declared but unpaid dividends on each
share of Series A Stock held by such holders. If upon the occurrence of any
liquidation, dissolution or winding up of the Corporation, either voluntary or
involuntary, the assets and funds to be distributed among the holders of Series
A Stock shall be insufficient to permit the payment to such holders of the full
aforesaid preferential amount, the entire assets and funds of the Corporation
legally available for distribution shall be distributed ratably among the
holders of the Series A Stock in proportion to the preferential amount each such
holder is otherwise entitled to receive.

                  (ii) After payment to the holders of the Series A Stock of the
amount set forth in subsection (i), the entire remaining assets and funds of the
Corporation legally 



                                       2.
<PAGE>   3

available for distribution, if any, shall be distributed ratably among the
holders of the Common Stock in proportion to the number of shares then held by
such holders.

                  (iii) For purposes of this subsection (d), a merger or
consolidation of the Corporation with or into any other corporation or
corporations, or the merger of any other corporation or corporations into the
Corporation in which the holders of the Corporation's outstanding Common Stock
immediately prior to the effective date of such transaction do not hold at least
fifty percent (50%) of all outstanding voting securities of the surviving
entity, or a sale of all or substantially all of the assets of the Corporation,
shall be treated as a liquidation, dissolution or winding up of the Corporation.

         (e) VOTING RIGHTS. Except as otherwise required by law, the shares of
the Series A Stock shall be voted together with this Corporation's Common Stock
as a single class at any annual or special meeting of stockholders of this
Corporation, or may act by written consent in the same manner as this
Corporation's Common Stock. Each share of Common Stock shall be entitled to one
vote. The holder of each share of Series A Stock shall be entitled to the number
of votes equal to the number of shares of Common Stock into which such share of
Series A Stock could be converted on the record date for the vote or, if no such
record date is established, at the date such vote is taken or any written
consent is solicited (in each case assuming such share is convertible as of such
date notwithstanding the time limitation on any such conversion set forth in
Section 2(f)(i)), shall have voting rights and powers equal to the voting rights
and powers of the Common Stock, and shall be entitled to notice of any
stockholders meeting in accordance with the Bylaws of this Corporation in the
same manner and to the same extent as holders of the Common Stock. Fractional
votes shall not be permitted, however, and any fractional voting rights
resulting from the above formula (after aggregating all shares into which shares
of Series A Stock held by each holder could be converted) shall be rounded to
the nearest whole number (with one-half being rounded upward.)

         (f) CONVERSION. The holders of the Series A Stock shall have the
following rights and shall be subject to the following restrictions with respect
to the conversion of the Series A Stock into shares of Common Stock:

                  (i) CONVERSION AT THE OPTION OF THE HOLDER. Each share of
Series A Stock shall be convertible, at the option of the holder thereof,
without the payment of additional consideration, at any time after January 1,
1999, at the office of the Corporation or any transfer agent for the Series A
Stock, into such number of fully paid and nonassessable shares of Common Stock
as is determined by dividing two dollars ($2.00) by the greater of (A) $6.00 and
(B) the then applicable Conversion Price, determined as provided in subsection
(f)(iii).



                                       3.
<PAGE>   4

                  (ii) AUTOMATIC CONVERSION. Each share of Series A Stock shall
automatically be converted into fully paid and nonassessable shares of Common
Stock effective as of 5:30 p.m. East Coast Time on the earlier of:

                           (1) at the close of business on the day on which the
Board of Directors shall have duly and unanimously adopted a resolution
requesting such conversion, in which case the number of shares of Common Stock
issuable upon conversion of each Share of Series A Stock shall be determined by
dividing two dollars ($2.00) by the then applicable Conversion Price, determined
as provided in subsection (f)(iii); and

                           (2) at the close of business on the first business
day following the date on which the average of the closing per share sales price
of the Common Stock as reported on the Nasdaq National Market (or any other U.S.
securities market or exchange on which the Common Stock may trade) for twenty
(20) consecutive trading days equals or exceeds nine dollars ($9.00) per share
(subject to adjustment for any stock splits, stock dividends, stock
consolidations or the like) (the "Average Price"), in which case the number of
shares of Common Stock issuable upon conversion of each such share of Series A
Stock shall be determined by dividing two dollars ($2.00) by the Average Price.

                  (iii) CONVERSION PRICE. In the case of conversion under
subsections (f)(i) and (f)(ii)(1), the conversion price for the Series A Stock
shall be equal to the average of the closing sales prices of the Common Stock as
traded on the Nasdaq National Market (or any other U.S. securities market or
exchange on which the Common Stock may trade) during the twenty (20) trading day
period ending on the day that is two (2) days prior to the date on which
conversion is requested by the Company or the holder, as the case may be (the
"Conversion Price"). Such Conversion Price shall be adjusted from time to time
in accordance with this subsection (f). All references to the Conversion Price
herein shall mean the Conversion Price as so adjusted.

                  (iv) MECHANICS OF CONVERSION. No fractional shares of Common
Stock shall be issued upon conversion of Series A Stock. In lieu of any
fractional shares to which the holder would otherwise be entitled, the
Corporation shall pay cash equal to such fraction multiplied by the then
effective Conversion Price. Before any holder of Series A Stock shall be
entitled to convert the same into full shares of Common Stock pursuant to
subsection (f)(i), it shall surrender the certificate or certificates therefor,
duly endorsed, at the office of the Corporation or of any transfer agent for the
Series A Stock, and shall give written notice to the Corporation at such office
that it elects to convert the same. Such conversion shall be deemed to have been
made immediately prior to the close of business on the date of such surrender of
the shares of Series A Stock to be converted, and the person or persons entitled
to receive the shares of Common Stock issuable upon such conversion shall be
treated for all purposes as the record holder or holders of such shares of
Common 



                                       4.
<PAGE>   5

Stock on such date. In the event of a conversion pursuant to subsection (f)(ii),
such conversion shall be deemed to have occurred automatically without any
further action by the Corporation or the holder as of the day specified in
subsection (f)(ii), and the person or persons entitled to receive the shares of
Common Stock issuable upon such conversion shall be treated for all purposes as
the record holder or holders of such shares of Common Stock on such date;
provided, however, that before any holder of Series A Stock shall be entitled to
receive a certificate representing the shares of Common Stock into which such
holder's shares of Series A Stock have been converted into pursuant to
subsection (f)(ii), it shall surrender the certificate or certificates
representing such shares of Series A Stock, duly endorsed, at the office of the
Corporation or of any transfer agent for the Series A Stock. The Corporation
shall, as soon as practicable after receipt of such surrendered certificates and
notice, if applicable, issue and deliver at such office to such holder of Series
A Stock a certificate or certificates, registered in such names as specified by
the holder, for the number of shares of Common Stock to which he shall be
entitled as aforesaid and a check payable to the holder in the amount of any
cash amounts payable as the result of a conversion into fractional shares of
Common Stock.

                  (v)      ADJUSTMENTS TO CONVERSION PRICE.

                           (1) In the event the Corporation shall at any time or
from time to time make or issue, or fix a record date for the determination of
holders of Common Stock entitled to receive, a dividend or other distribution
payable in securities of the Corporation or any of its subsidiaries other than
shares of Common Stock, then in each such event provision shall be made so that
the holders of Series A Stock shall receive, upon the conversion thereof, the
securities of the Corporation which they would have received had their stock
been converted into Common Stock on the date of such event.

                           (2) If there occurs any capital reorganization or any
reclassification of the capital stock of the Corporation (other than any event
provided for in subsection (f)(v)(1) above), each share of Series A Stock shall
thereafter be convertible into the same kind and amounts of securities or other
assets, or both, that were issuable or distributable to the holders of shares of
outstanding Common Stock upon such reorganization or reclassification, in
respect of that number of shares of Common Stock into which such shares of
Series A Stock might have been converted immediately prior to such
reorganization or reclassification; and in any such case, appropriate
adjustments (as determined by the Board of Directors) shall be made in the
application of the provisions herein set forth with respect to the rights and
interests thereafter of the holders of Series A Stock to the end that the
provisions of this Article IV shall thereafter be applicable, as nearly as
reasonably may be, in relation to any securities or other assets thereafter
deliverable upon the conversion of the Series A Stock.



                                       5.
<PAGE>   6

                           (3) Upon the occurrence of each adjustment or
readjustment of the number or kind of shares issuable upon conversion of a share
of Series A Stock pursuant to this subsection (f)(v), the Corporation at its
expense shall promptly compute such adjustment or readjustment in accordance
with the terms hereof and prepare and furnish to each holder of Series A Stock a
certificate setting forth such adjustment or readjustment and showing in detail
the facts upon which such adjustment or readjustment is based. The Corporation
shall, upon the written request at any time of any holder of Series A Stock,
furnish or cause to be furnished to such holder a like certificate prepared by
the Corporation setting forth (i) such adjustments and readjustments, and (ii)
the number of shares and the amount, if any, of other property which at the time
would be received upon the conversion of Series A Stock.

                  (vi) NOTICES OF RECORD DATE. In the event of any taking by the
Corporation of a record of the holders of any class of securities for the
purpose of determining the holders thereof who are entitled to receive any
dividend (other than a cash dividend) or other distribution, any security or
right convertible into or entitling the holder thereof to receive additional
shares of Common Stock, or any right to subscribe for, purchase or otherwise
acquire any shares of stock of any class or any other securities or property, or
to receive any other right, the Corporation shall mail to each holder of Series
A Stock at least 30 days prior to the date specified therein, a notice
specifying the date on which any such record is to be taken for the purpose of
such dividend, distribution, security or right, and the amount and character of
such dividend, distribution, security or right.

                  (vii) ISSUE TAXES. The holders of Series A Stock shall pay any
and all issue, transfer and other taxes that may be payable in respect of any
issue or delivery of shares of Common Stock on conversion of shares of Series A
Stock pursuant hereto.

                  (viii) RESERVATION OF STOCK ISSUABLE UPON CONVERSION. The
Corporation shall at all times reserve and keep available out of its authorized
but unissued shares of Common Stock, solely for the purpose of effecting the
conversion of the shares of the Series A Stock, such number of its shares of
Common Stock as shall from time to time be sufficient to effect the conversion
of all outstanding shares of the Series A Stock; and if at any time the number
of authorized but unissued shares of Common Stock shall not be sufficient to
effect the conversion of all then outstanding shares of the Series A Stock, the
Corporation will take such corporate action as may, in the opinion of its
counsel, be necessary to increase its authorized but unissued shares of Common
Stock to such number of shares as shall be sufficient for such purpose,
including, without limitation, engaging in best efforts to obtain the requisite
stockholder approval of any necessary amendment to the Articles of
Incorporation.

                  (ix) NOTICES. Any notice required by the provisions of this
Section 2 to be given to the holders of shares of Series A Stock shall be deemed
given if deposited in the 



                                       6.
<PAGE>   7

United States mail, postage prepaid, and addressed to each holder of record at
its address appearing on the books of the Corporation.

         (g) NO REISSUANCE OF SERIES A STOCK. No share or shares of Series A
Stock acquired by the Corporation by reason of conversion or otherwise shall be
reissued. In the event of any such conversion or other acquisition, the shares
so issued or acquired shall revert to the status of authorized but unissued
shares of Preferred Stock."

         ARTICLE VII shall be amended and restated to read in its entirety as
follows:

"1. The number of directors which shall constitute the whole Board of Directors
shall be fixed exclusively by one or more resolutions adopted by a majority of
the total number of authorized directors (whether or not there exist any
vacancies in previously authorized directorships at the time any such resolution
is presented to the Board for adoption).

2. Subject to the rights of the holders of any series of Preferred Stock (other
than the Series A Stock) to elect additional directors under specified
circumstances, the directors shall be divided into three classes as nearly equal
in size as practicable designated as Class I, Class II and Class III,
respectively. Directors shall be assigned to each class in accordance with a
resolution or resolutions adopted by the Board of Directors. At the first annual
meeting of stockholders following the adoption and filing of this Certificate of
Amendment of Certificate of Incorporation, the term of office of the Class I
directors shall expire and Class I directors shall be elected for a full term of
three years. At the second annual meeting of stockholders following the adoption
and filing of this Certificate of Amendment of Certificate of Incorporation, the
term of office of the Class II directors shall expire and Class II directors
shall be elected for a full term of three years. At the third annual meeting of
stockholders following the adoption and filing of this Certificate of Amendment
of Certificate of Incorporation (the "First Class Three Meeting"), the term of
office of the Class III directors shall expire and Class III directors shall be
elected for a full term of three years. At each succeeding annual meeting of
stockholders, directors shall be elected for a full term of three years to
succeed the directors of the class whose terms expire at such annual meeting.

         Notwithstanding the foregoing provisions of this Article, each director
shall serve until his successor is duly elected and qualified or until his
death, resignation or removal. No decrease in the number of directors
constituting the Board of Directors shall shorten the term of any incumbent
director.

3. The Board of Directors or any individual director may be removed from office
at any time (i) with cause by the affirmative vote of the holders of a majority
of the voting power of all the then-outstanding shares of voting stock of the
Corporation entitled to vote at an election of directors (the "Voting Stock") or
(ii) without cause by (1) until the First 



                                       7.
<PAGE>   8

Class III Meeting, the affirmative vote of the holders of at least eighty
percent (80%) of the voting power of all the then-outstanding shares of the
Voting Stock, and (2) after the First Class III Meeting, the affirmative vote of
at least sixty-six and two-thirds percent (66 2/3%) of the voting power of all
the then-outstanding shares of the Voting Stock."

FOURTH: Thereafter, pursuant to a resolution of the Board of Directors, this
Certificate of Amendment was submitted to the stockholders of the Corporation
for their approval, and was duly adopted in accordance with the provisions of
Section 242 of the General Corporation Law of the State of Delaware.


                                       8.
<PAGE>   9

         IN WITNESS WHEREOF, the undersigned, James L. Lambert and Dana W.
Kammersgard, have signed this Certificate of Amendment as President and
Secretary, respectively, of the Corporation, this 31st day of March, 1998.



                                             /s/ JAMES L. LAMBERT
                                             -----------------------------------
                                             James L. Lambert, President



                                             /s/ DANA W. KAMMERSGARD
                                             -----------------------------------
                                             Dana W. Kammersgard, Secretary



                                       9.