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                                                                   EXHIBIT 10.21


                         SEVERANCE AND RELEASE AGREEMENT

     This Severance and Release Agreement (the "Agreement") is made and entered
into by and between Guy M. Cheney ("Cheney") and MTI Technology Corporation
("MTI" or "the Company"), and shall become effective on the Effective Date (as
defined in Section 5b, below).

                                    RECITALS

     On or about August 28, 2000, Cheney commenced employment with MTI as the
Company's Vice President and Corporate Controller.

     On April 6, 2001, MTI and Cheney mutually agreed to terminate Cheney's
employment, effective April 6, 2001. MTI does not have a uniform policy or
practice of granting particular severance benefits to its employees or
executives. However, MTI offered to pay to Cheney only those severance benefits
described in the paragraphs that follow in exchange for Cheney's release of all
claims against the Company. Cheney accepted this offer.

     NOW, THEREFORE, in consideration of the recitals listed above, and the
mutual promises contained in this Agreement, Cheney and the Company agree,
covenant, and represent as follows:


                                    AGREEMENT

     1.   The Parties' Responsibilities

          a. Upon the Effective Date of this Agreement, MTI shall pay to Cheney
a one-time lump sum payment in the total gross amount of $85,600 (the "Severance
Payment"). Cheney acknowledges that MTI shall withhold from the Severance
Payment all applicable payroll taxes, including federal and state income taxes,
as well as other authorized deductions. Cheney acknowledges that, but for
entering into this Agreement, he would not be entitled to the Severance Payment.

          b. Effective April 7, 2001, MTI and Cheney agree that Cheney shall be
retained by MTI as a consultant to the terms and conditions of the Consulting
Agreement attached hereto as Exhibit A (the "Consulting Agreement").

          c. Subject to the approval of MTI's Board of Directors' Compensation
Committee, MTI agrees that Cheney's service as a consultant shall constitute
Continuing Status as an Employee, Director, or Consultant for purposes of the
Company's 1996 Stock Incentive Plan, and that Cheney's Option Agreements shall
remain in full force and effect during the term of the Consulting Period. Cheney
understands and agrees that his right to exercise these shares shall be in
accordance with the terms and conditions set forth in his Option Agreements with
MTI and the MTI Technology Corporation 1996 Stock Incentive Plan, as amended
(the "Stock Incentive Plan").


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          d. Cheney acknowledges that, as of May 1, 2001, he may be eligible to
obtain continuing coverage under MTI's group medical plan pursuant to the
provisions of the Consolidated Omnibus Reconciliation Act and its implementing
regulations ("COBRA"). From May 1, 2001 through October 31, 2001, MTI will pay
the premium payments for any COBRA continuation coverage that Cheney elects to
obtain. In addition, from May 1, 2001 through October 31, 2001, MTI will
reimburse Cheney for medical expenses (and life insurance) incurred by Cheney
that are not covered by his COBRA continuation coverage but that would be
covered under MTI's Executive Medical Plan. In no event shall MTI be liable for,
or required to pay premiums for any COBRA continuation coverage Cheney may elect
or be eligible to obtain after October 31, 2001.

          e. MTI will also pay reasonable, documented costs incurred by Cheney
to receive tax and estate planning services, in an amount not to exceed $3,200.
Cheney may recommend and request a specific person or firm to provide the tax
and estate planning services.

          f. MTI will allow Cheney to keep the MTI cellular telephone that he is
currently using. MTI will pay for 1000 chargeable minutes from the Effective
Date of this Agreement until on or before May 15, 2001. Any charges made by
Cheney above the 1000 chargeable minutes will be Cheney's sole responsibility to
pay, and Cheney will reimburse MTI for any amounts that it incurs for his usage
above 1000 chargeable minutes. Effective May 15, 2001, MTI will reassign the
cellular telephone number to Cheney, and Cheney will be responsible for all
charges and costs associated with use of the cellular telephone.

     2.   Release

          a. In consideration of the promises specified in this Agreement and
for other good and valuable consideration, the receipt and adequacy of which are
hereby acknowledged, Cheney, for himself and his heirs, assigns, executors,
administrators, and agents, past and present (collectively, the "Cheney
Affiliates"), hereby fully and without limitation releases, covenants not to
sue, and forever discharges MTI and its respective subsidiaries, divisions,
affiliated corporations, affiliated partnerships, parents, trustees, directors,
officers, shareholders, partners, agents, employees, representatives,
consultants, attorneys, heirs, assigns, executors and administrators,
predecessors and successors, past and present (collectively with MTI, the "MTI
Releasees"), both individually and collectively, from any and all rights,
claims, demands, liabilities, actions and causes of action whether in law or in
equity suits, damages, losses, workers' compensation claims, attorneys' fees,
costs, and expenses, of whatever nature whatsoever, known or unknown, fixed or
contingent, suspected or unsuspected ("Claims"), that Cheney or the Cheney
Affiliates now have, or may ever have, against any of the MTI Releasees that
arise out of, or are in any way related to: (i) Cheney's employment by MTI or
any of the other MTI Releasees; (ii) the termination of Cheney's employment by
MTI or any of the other MTI Releasees; and (iii) any transactions, occurrences,
acts or omissions by MTI or any of the other MTI Releasees occurring prior to
the Effective Date of this Agreement.

          b. Without limiting the generality of the foregoing, Cheney
specifically and expressly releases any Claims occurring prior to the Effective
Date of this Agreement arising out of or related to violations of any federal or
state employment discrimination law, including the California Fair Employment
and Housing Act; Title VII of the Civil Rights Act of 1964; the


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Americans with Disabilities Act; the Age Discrimination In Employment Act; the
National Labor Relations Act; the Equal Pay Act; the Employee Retirement Income
Security Act of 1974; as well as Claims arising out of or related to violations
of the provisions of the California Labor Code; state and federal wage and hour
laws; breach of contract; fraud; misrepresentation; common counts; unfair
competition; unfair business practices; negligence; defamation; infliction of
emotional distress; invasion of privacy; assault; battery; false imprisonment;
wrongful termination; and any other state or federal law, rule, or regulation.

          c. Cheney represents that he did not suffer any work-related injuries
while employed by the Company, that he has no intention of filing any claims for
workers' compensation benefits of any type against the Company, and that he will
not file or attempt to file any claims for workers' compensation benefits of any
type against the MTI Releasees. Cheney acknowledges that the Company has relied
upon these representations, and that the Company would not have entered into
this Agreement but for these covenants and representations. As a result, Cheney
agrees, covenants, and represents that the Company or any of the other Releasees
may, but are not obligated to, submit this Agreement to the Workers'
Compensation Appeals Board for approval as a compromise and release as to any
such new or unasserted workers' compensation claims or any of the other
Releasees.

     3.   Release By The Company.

     The Company hereby fully and without limitation releases, covenants not to
sue, and forever discharges Cheney from any and all Claims that the Company now
has, or may ever have, against Cheney for any acts or omissions by the Cheney
occurring prior to the Effective Date of this Agreement. Notwithstanding the
foregoing, Cheney and the Company agree that the release provisions of this
Section 3 shall not apply to any Claims that the Company may have against Cheney
for embezzlement or any other fraudulent acts that Cheney may have committed
against, or while employed by, the Company.

     4.   RELEASE APPLIES TO KNOWN AND UNKNOWN CLAIMS.

     Cheney and the Company acknowledge that they are aware of and familiar with
the provisions of Section 1542 of the California Civil Code, which provides as
follows:

          "A general release does not extend to claims which the creditor does
          not know or suspect to exist in him favor at the time of executing the
          release, which if known by him, must have materially affected his
          settlement with the debtor."

     Cheney and the Company hereby waive and relinquish all rights and benefits
that they may have under Section 1542 of the California Civil Code, or the law
of any other state or jurisdiction, or common law principle, to the same or
similar effect. Notwithstanding the foregoing, the Company's waiver of its
rights under Section 1542 shall not apply to any claims that it may have against
Cheney for embezzlement or any other fraudulent acts that Cheney may have
committed against, or while employed by, the Company.


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     5.   Older Worker's Benefit Protection Act.

          a. This Agreement is subject to the terms of the Older Workers Benefit
Protection Act of 1990 (the "OWBPA"). The OWBPA provides that an individual
cannot waive a right or claim under the Age Discrimination in Employment Act
("ADEA") unless the waiver is knowing and voluntary. Pursuant to the terms of
the OWBPA, Cheney acknowledges and agrees that he has executed this Agreement
voluntarily, and with full knowledge of its consequences.

          b. In addition, Cheney hereby acknowledges and agrees that: (a) this
Agreement has been written in a manner that is calculated to be understood, and
is understood, by Cheney; (b) the release provisions of this Agreement apply to
any rights that Cheney may have under the ADEA, including the right to file a
lawsuit against the Company for age discrimination; (c) the release provisions
of this Agreement do not apply to any rights or claims that Cheney may have
under the ADEA that arise after the date he executes this Agreement; (d) the
Company does not have a preexisting duty to pay the settlement payment
identified in this Agreement; (e) Cheney has been advised in writing to consult
with an attorney prior to executing this Agreement; (f) Cheney shall have a
period of 21 days in which to consider the terms of this Agreement prior to its
execution; and (g) Cheney shall have a period of seven days after execution of
this Agreement in which to revoke this Agreement. Cheney further understands
that this Agreement shall not become effective until expiration of this
seven-day period (the "Effective Date").

     6.   Confirmation of Payment of Wages.

     Cheney acknowledges that he has been paid all wages and other compensation
due and owing to him from the Company as of the Effective Date of this
Agreement, including all commissions, bonuses, and accrued vacation.
Accordingly, Cheney understands that the release provisions of Section 2 of this
Agreement release and discharge the Company from any and all claims that he may
have against the Company for unpaid wages and other compensation including, but
not limited to, any claims for salary; bonuses; commissions; stock; stock
options; other securities, or any other ownership interests or rights to
acquire, directly or indirectly, ownership interests in the Company; vacation
pay; fringe benefits; expense reimbursements; severance pay; or any other form
of compensation not listed as part of this Agreement.

     7.   Confidentiality and Non-Disparagement

          a. Cheney and the Company agree, covenant and represent that the facts
relating to the existence of this Agreement, the negotiations leading to the
execution of this Agreement, and the terms of this Agreement shall be held in
confidence, and shall not be disclosed, communicated, offered into evidence in
any legal proceeding, or divulged to any person other than those who must
perform tasks to effectuate this Agreement. Notwithstanding the foregoing, the
parties may disclose the terms of this Agreement to those persons to whom
disclosure is necessary for the preparation of tax returns and other financial
reports, the obtaining of legal advice, and to persons to whom disclosure is
ordered by a court of competent jurisdiction or otherwise required by law
(including the Securities Exchange Act of 1934 and the regulations of the


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NASDAQ Stock Exchange) or by obligation to owners, shareholders, partners, or
members of the Company.

          b. Cheney further agrees, covenants and represents that he shall not
take any action or make any comments that actually or potentially disparage,
disrupt, damage, impair, or otherwise interfere with MTI's business interests or
reputation.

          c. The Company agrees, covenants, and represents that it will use its
best efforts to prevent Paul Emery, Tom Raimondi, Dale Wight, and other
employees from taking any action or making any comments that actually or
potentially disparage Cheney.

     8.   Trade Secrets

          Cheney acknowledges that he executed a Proprietary Information
Agreement and that he shall continue to be bound by this Proprietary Information
Agreement following the termination of his employment with MTI. A copy of the
Proprietary Information Agreement is attached to this Agreement as Exhibit B.
Without limiting in any way the terms of the Proprietary Information Agreement,
Cheney agrees that he will not disclose over the Internet any confidential,
proprietary, or trade secret information of the Company.

     9.   Non-Admission of Liability

          This Agreement shall not be treated as an admission of liability by
either party, at any time or for any purpose, and this Agreement shall not be
admissible in any proceeding between the parties except a proceeding relating to
a breach of its provisions after execution, or a proceeding to obtain approval
of the Agreement as a compromise and release as provided in Section 2(c) of this
Agreement

     10.  Arbitration of Disputes

          a. MTI and Cheney agree that, to the fullest extent permitted by law,
any and all claims or controversies between them (or between Cheney and any
present or former officer, director, agent, or employee of the Company or any
parent, subsidiary, or other entity affiliated with the Company) relating in any
manner to Cheney's employment or the termination of Cheney's employment shall be
resolved by final and binding arbitration in accordance with the then-existing
National Rules for the Resolution of Employment Disputes of the American
Arbitration Association (the "AAA Rules"). Claims subject to arbitration shall
include, but are not limited to: contract claims, tort claims, claims relating
to compensation and stock options, as well as claims based on any federal,
state, or local law, statute, or regulation, including but not limited to any
claims arising under Title VII of the Civil Rights Act of 1964, the Age
Discrimination in Employment Act, the Americans with Disabilities Act, and the
California Fair Employment and Housing Act. However, claims for unemployment
compensation, workers' compensation, and claims under the National Labor
Relations Act shall not be subject to arbitration.

          b. The arbitrator shall prepare a written decision containing the
essential findings and conclusions on which the award is based so as to ensure
meaningful judicial review


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of the decision. The arbitrator shall apply the same substantive law, with the
same statutes of limitations and same remedies, that would apply if the claims
were brought in a court of law. The arbitrator shall have the authority to rule
on a motion to dismiss and/or summary judgment by either Cheney or the Company
and shall apply the standards governing such motions under the California Code
of Civil Procedure.

          c. The parties may bring an action in court to compel arbitration
under this Agreement and to enforce an arbitration award. Otherwise, neither
party shall initiate or prosecute any lawsuit or administrative action in any
way related to any arbitrable claim, including without limitation any claim as
to the making, existence, validity, or enforceability of the agreement to
arbitrate. Nothing in this Agreement precludes a party from filing an
administrative charge before an agency that has jurisdiction over an arbitrable
claim. All arbitration hearings under this Agreement shall be conducted in
Orange County, California. Notwithstanding the foregoing, either party may, at
its option, seek injunctive relief in a court of competent jurisdiction for any
claim or controversy arising out of or related to the unauthorized use,
disclosure, or misappropriation of the confidential and/or proprietary
information of either party.

          d. THE PARTIES UNDERSTAND THAT THIS SECTION 10 CONSTITUTES A WAIVER OF
THEIR RIGHT TO A TRIAL BY JURY OF ANY CLAIMS OR CONTROVERSIES COVERED BY THIS
AGREEMENT, AND THAT NONE OF THOSE CLAIMS OR CONTROVERSIES SHALL BE RESOLVED BY A
JURY TRIAL.

          e. The arbitration provisions of this Section 10 shall be governed by
the Federal Arbitration Act ("FAA"), unless a court of competent jurisdiction
determines the FAA to be inapplicable, in which case the parties agree that the
California Arbitration Act (Code Civil Procedure ss. 1280 et seq.) shall apply.
In all other respects, this Section 10 is to be construed in accordance with the
laws of the State of California, without reference to conflicts of law
principles.


     11.  Successors and Assigns

          This Agreement shall be binding upon and shall inure to the benefit of
the respective heirs, assigns, executors, administrators, successors,
subsidiaries, divisions and affiliated corporations and partnerships, past and
present, and trustees, directors, officers, shareholders, partners, agents and
employees, past and present, of Cheney and MTI.

     12.  Ambiguities

          This Agreement has been reviewed by the parties. The parties have had
a full opportunity to negotiate the terms and conditions of this Agreement.
Accordingly, the parties expressly waive any common-law or statutory rule of
construction that ambiguities should be construed against the drafter of this
Agreement, and agree, covenant, and represent that the language in all parts of
this Agreement shall be in all cases construed as a whole, according to its fair
meaning.


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     13.  Choice of Law

          This Agreement has been negotiated and executed in the State of
California and is to be performed in Orange County, California. This Agreement
shall be governed by and interpreted in accordance with the laws of the State of
California, including all matters of construction, validity, performance, and
enforcement, without regard to California's conflict of laws rules.

     14.  Integration

          This Agreement; Cheney's Option Agreements with the Company; and the
Proprietary Information Agreement attached as Exhibit B constitute a single,
integrated written contract expressing the entire agreement of the parties.
There is no other agreement, written or oral, express or implied, between the
parties with respect to the subject matter hereof. This Agreement may not be
orally modified. This Agreement may only be modified in a written instrument
signed by both parties.

     15.  Severability

          The parties to this Agreement agree, covenant and represent that each
and every provision of this Agreement shall be deemed to be contractual, and
that they shall not be treated as mere recitals at any time or for any purpose.
Therefore, the parties further agree, covenant and represent that each and every
provision of this Agreement shall be considered severable, except for the
Release provisions of Sections 2 and 4 of this Agreement. If a court of
competent jurisdiction finds the release provisions of Sections 2 or 4 of this
Agreement to be unenforceable or invalid, then this Agreement shall become null
and void, and the Severance Payment paid to Cheney pursuant to Section 1 shall
be returned to MTI within 15 days. If a court of competent jurisdiction finds
any provision other than the release provisions of Sections 2 or 4, or part
thereof, to be invalid or unenforceable for any reason, that provision, or part
thereof, shall remain in force and effect to the extent allowed by law, and all
of the remaining provisions of this Agreement shall remain in full force and
effect and enforceable.

     16.  Execution of Counterparts

          This Agreement may be executed in counterparts, and if so executed and
delivered, all of the counterparts together shall constitute one and the same
Agreement.

     17.  Captions

          The captions and section numbers in this Agreement are inserted for
the readers' convenience, and in no way define, limit, construe or describe the
scope or intent of the provisions of this Agreement.


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     18.  Representations And Warranties

          a. Cheney represents and warrants that he has the authority to enter
into this Agreement and to bind all persons and entities claiming through him.

          b. Cheney represents that he has read this Agreement and fully
understands all of its terms; that MTI has advised him to consult with an
attorney, and that he has conferred with his attorneys or has knowingly and
voluntarily chosen not to confer with his attorneys about this Agreement; that
he has executed this Agreement without coercion or duress of any kind; and that
he understands any rights that he has or may have and signs this Agreement with
full knowledge of any such rights.

          c. Cheney acknowledges that no representations, statements or promises
made by MTI, or by its agents or attorneys, has been relied on in entering into
this Agreement.

     The undersigned have read the foregoing Agreement and accept and agree to
the provisions contained therein, and hereby execute it, knowingly and
voluntarily, and with full understanding of its consequences.

     IF CHENEY SIGNS THIS AGREEMENT BEFORE THE 21-DAY REVIEW PERIOD PROVIDED BY
SECTION 5(b)(f), CHENEY ACKNOWLEDGES AND AGREES THAT HE HAS VOLUNTARILY WAIVED
THE REVIEW PERIOD.

     IN WITNESS WHEREOF, the parties hereto have executed this Agreement, which
consists of 8 pages, on the dates indicated below.

GUY M. CHENEY                                MTI TECHNOLOGY CORPORATION

SIGNATURE:                                   SIGNATURE:
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DATE:                                        NAME:
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                                             TITLE:
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                                             DATE:
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