Digital Technical Journal, Volume 6, Number 4: RAID Array Controllers
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RAID Away Controllers Workflvw Models PC LAN and System Management Tools Digital Technical Journal Digital Equipment Corporation Editorial Advisory Board Jane C. Blake, Managing Editor Samuel H. Fuller, Chairman Kathleen M. Stetson, Editor Richard W Beane Helen L. Patterson, Editor Donald 2. Harbert Circulation William R. Hawe Catherine M. Phillips, Administrator RichardJ. Hollingsworth Dorothea B. Cassady, Secretary Richard E Lary Alan G. Nemeth Production Jean A. Proulx Terri Autieri, Production Editor Robert M. Supnik Anne S. Katzeff, Typographer Gayn B. Winters Peter R. Woodbury, Illustrator The Digital TechnicalJournal is a refereed journal published quarterly by Digital Equipment Corporation, 30 Porter Road LJ02/D10, Littleton, Massachusetts 01460. Subscriptionsto the Journal are $40.00 (non-U.S. $60) for four issues and $75.00 (non-U.S. $115) for eight issues and must be prepaid in U.S. funds. University and college professors and Ph.D. students in the electrical engineering and computer science fields receive complimentary subscriptions upon request. Orders, inquiries, and address changes should be sent to the Digital TechnicalJournal at the published- by address. Inquiries can also be sent electronically to [email protected] copies and back issues are available for $16.00 each by calling DECdirect at 1-800-DIGITAL (1-800-344-4825). Recent back issues of the Journal are also available on the Internet at http://www.digital.com/info/DTJ/home.html. Complete Digital Internet listings can be obtained by sending an electronic mail message to [email protected]. Digital employees may order subscriptions through Readers Choice by entering VTX PROFILE at the system prompt. Comments on the content of any paper are welcomed and may be sent to the managing editor at the published-by or network address. Copyright O 1995 Digital Equipment Corporation. Copying without fee is permitted provided that such copies are made for use in educational institutions by faculty mem- bers and are not distributed for commercial advantage. Abstracting with credit of Digital Equipment Corporation's authorship is permitted. All rights reserved. The information in theJournal is subject to change without notice and should not be construed as a commitment by Digital Equipment Corporation or by the companies herein represented. Digital Equipment Corporation assumes no responsibility for any errors that may appear in the Journal. ISSN 0898-901X Documentation Number EY-T118E-TJ The following are trademarks of Digital Equipment Corporation:AXE CI, DEC, DEC OSF/l, DECmcc, DECmodel, DECnet, DECwindows, Digital, the DIGITAL logo, HSC, HSCSO, HSC60, HSC70, HSC90, HSJ, HSZ, Infoserver, KDM, ManageWORKS, ObjectFlow, OpenVMS, PATHWORKS POLYCENTER, Storageworks, ULTRIX, VAX, VAXcluster, VAXstation, VMS, and VMScluster. Apple and Appleshare are registered trademarks of Apple Computer, Inc. dBase N is a registered trademark of Borland International, Inc. Cover Design Hewlett-Packard is a registered trademark of Hewlett-Packard Company Our cover design is inspired by a system man- i960 is a trademark of Intel Corporation. agement topic in this issue. ManageWORKS IBM and NetView are registered trademarks of International Business Machines software is a system and network manage- Corporation. ment tool thatpresents an object-oriented, Knowledge Craft is a registered trademark of Carnegie Group, Inc. Microsoft and Visual C++ are registered trademarks and Windows and Windows NT graphical view of a heterogeneous LAN envi- are trademarks of Microsoft Corporation. ronment. The multicolor circles on the cover NFS is a registered trademark of Sun Microsystems, Inc. represent the diverse objects, or entities, on the networks among which a system adminis- NetWare and Novell are registered trademarks of Novell, Inc. trator "navigates"using the integrated com- OSF/l is a registered trademark of the Open Software Foundation, Inc. ponents of the tool. Sun Microsystems is a registered trademark of Sun Microsystems, Inc. UNM is a registered trademark in the United States and other countries, licensed The cover was designed by Lucinda O'Neill exclusively by X/Open Company Ltd. and Joe Pozerycki,Jr, of Digital's Design X Window System is a trademark of the Massachusetts Institute of Technology. Group. Book production was done by Quantic Communications, Inc. I Contents RAW Array Controllers 5 The Architecture and Design of HS-series Storageworks Array Controllers Stephen J. Sicola Workflow Models 26 Policy Resolution in Work* Management System Christoph J. Bugler 50 The Design of DECmodelfor Windows Stewart \! Hoover and Gar). L. Kratkiewicz PC LAN and System Management Tools 63 The Design of ManageWORKS: A User Interface Framework Dennis G. Giokas and John C. Rokicki 75 The Structure of the OpenVMS Management Station James E. Johnson 89 Autotnatic, Network-directed Operatirtg System SoBware Upgrades:A Platform-independent Approach John R. Lawson, Jr. I Editor's Introduction explain the reasoning behind the creation of a pre- sentation layer it1 DE<;motlelth;~t provicles a graphi- cal view of the business process while hitling the technical cletails of the moclel. The authors also cover implementation details, including the deci- sions to move from the original I.1SI' etivironment to ;I <:++ programming environment and to imple- ment the knowletlge base for I>E<;modelin RO<:K, a frame-basecl knowleclge representation. We then shift the focus to lManagrWORKS and ['OIS<:ENTER tools thxt h;~vebeen clevelopetl to simplify tlie increasingly complic;itetl job of systeni Jane C. Blake management. The first of three papers tlescribes ~V~in~igingEditor the tlevelopment of the ManageWORKS IVorkgroup Administrator software. Dennis <;iokas ancl John Three computing topics ;Ire presentetl in this issue Rokicki tliscuss the tlesign principles adopted for of the Journcll: a storage array controller for open tliis product that enables system ant1 network man- system environments, workflow architectures ;inel agement of heterogeneous IANs from a single PC: tools, and PC and IAN system management proclucts. running >licrosoft Wintlows. Key design elements 'I'he opening paper, by Steve Sicola. describes are plug-in, c~~stomizablemoclules for system Digital's new HS series of Storageworks array con- navigation ancl maniigement, ant1 the user inter- trollers. Designed for open systems, the control- kite framework, which controls the flow between lers interface to host computers by means of the modules. The authors offer sce~lariosto illustrate industry-standard SCSI-2 interconnect, as well as interactions between components. Digital's C1 ant1 DSSI host interconnects. Equ;illy Managing OpenVMS systems fro~na PC running important to designers ;IS openness were controller the Microsoft Windows operating system can be availability ant1 performance. Innovative fe:eati~res accomplished with the OpcnViMS Management were introducetl, i~~cluclingclual-retlu~~tlant con- Stalion, of which ManageWOKKS is a key compo- trollers and Parity RtSII) firmware to ensure high nent. Jim Johnson tlefines tlie need for tliis scalable availability, ant1 a write-back cache that significantly ;ind secure client-server ~oo1in OpenVMS envi- improves performance. The paper concludes witli ronments, which can be clusterecl, distributed, a clescription of the common controller processing exp;eanded, and networked estetisively. After a dis- core for the SCSI, CI, ;lncl I>SSI controllervariants. cussion of design alternatives, Jim tlescribes the Workflow is the subject of two papers witli dif- firnctions of the Station's client, communication. fering perspectives. <:Iiristopli Bugler opens his ;in<\server components. paper with introductory definitions ancl implica- The final paper is about ;in initial s)~stemlo;ltl tions of workflow concepts. He argues that a work- (ISL) capability for ;l~ito~natic,network-tlirectetl. flow that uses roles for task ;Issignment is limited. operating systeni software upgr;ides. john Lawson especially in large. international enterprises. He reviews goals for the POLYCENTER Softw'ire Distri- states that by adding the dimension of organiza- bution layered product, compares the POLYCENTER tional tlependencies for task assignment a comples IsL process with the OpenVMS ISl. process. and workflow is more precisely expressed. Using the steps through the requirements tor expanding the example of a travel expense reimbursement work- I)OI.Y(:ENTER Software 1)istribution capability to flow, Christoph shows how tlie Policy Resolution other platforms and operating systems. Architecture tlesign principles support enterprise- Our next issue will celebrate the./o~~r~znl'stenth level workflow tleployment-reusabilit): security, ;uiniversary of publishing the technical acliieve- generality, dynamics, ant1 distribution. He also dis- ments of Digital's engineers and partners. The issue cusses the Policy Definition Language that formally will feature database technologies ant1 new Alpha describes workflow elements. workstations and high-end server systems. A second paper about workflow presents a tool, called DECmodel for Wintiows, for the development of business process nioclels ;11id their graphical presentation. Stew Hoover and Gary Kratkiewicz Biographies I Christoph J. BMler Christoph Bufiler is a faculty member at the Technical University of Darmstatlt, German): where he is pursuing a Ph.D. degree. His research is ui workflow and organization modeling, with a focus on organizational embedding of workflow management,