PART 1: BROCADE MAINFRAME CHAPTER 2 CONNECTIVITY SOLUTIONS The modern IBM mainframe, also known as IBM zEnterprise, has a distinguished 50-year history BROCADEMainframe I/O and as the leading platform for reliability, availability, serviceability, and scalability. It has transformed Storage Basics business and delivered innovative, game-changing technology that makes the extraordinary possible, and has improved the way the world works. For over 25 of those years, Brocade, MAINFRAME the leading networking company in the IBM mainframe ecosystem, has provided non-stop The primary purpose of any computing system is to networks for IBM mainframe customers. From parallel channel extension to ESCON, FICON, process data obtained from Input/Output devices. long-distance FCIP connectivity, SNA/IP, and IP connectivity, Brocade has been there with IBM CONNECTIVITY and our mutual customers. Input and Output are terms used to describe the SOLUTIONStransfer of data between devices such as Direct This book, written by leading mainframe industry and technology experts from Brocade, discusses Access Storage Device (DASD) arrays and main mainframe SAN and network technology, best practices, and how to apply this technology in your storage in a mainframe. Input and Output operations mainframe environment. are typically referred to as I/O operations, abbreviated as I/O. The facilities that control I/O operations are collectively referred to as the mainframe’s channel subsystem. This chapter provides a description of the components, functionality, and operations of the channel subsystem, mainframe I/O operations, mainframe storage basics, and the IBM System z FICON qualification process. STEVE GUENDERT DAVE LYTLE FRED SMIT Brocade Bookshelf www.brocade.com/bookshelf i BROCADE MAINFRAME CONNECTIVITY SOLUTIONS STEVE GUENDERT DAVE LYTLE FRED SMIT BROCADE MAINFRAME CONNECTIVITY SOLUTIONS ii © 2014 Brocade Communications Systems, Inc. All Rights Reserved. 06/14 ADX, AnyIO, Brocade, Brocade Assurance, the B-wing symbol, DCX, Fabric OS, HyperEdge, ICX, MLX, MyBrocade, OpenScript, VCS, VDX, and Vyatta are registered trademarks, and The Effortless Network and The On-Demand Data Center are trademarks of Brocade Communications Systems, Inc., in the United States and/or in other countries. Other brands, products, or service names mentioned may be trademarks of others. Notice: This document is for informational purposes only and does not set forth any warranty, expressed or implied, concerning any equipment, equipment feature, or service offered or to be offered by Brocade. Brocade reserves the right to make changes to this document at any time, without notice, and assumes no responsibility for its use. This informational document describes features that may not be currently available. Contact a Brocade sales office for information on feature and product availability. Export of technical data contained in this document may require an export license from the United States government. Brocade Mainframe Connectivity Solutions Written by Steve Guendert, Dave Lytle, Fred Smit Project Managed by Diane Andrada Edited by Jan Richardson Design and Production by Diane Andrada and Malika Henderson Illustrated by Diane Andrada and David Lehmann IMPORTANT NOTICE Use of this book constitutes consent to the following conditions. This book is supplied “AS IS” for informational purposes only, without warranty of any kind, expressed or implied, concerning any equipment, equipment feature, or service offered or to be offered by Brocade. Brocade reserves the right to make changes to this book at any time, without notice, and assumes no responsibility for its use. This informational document describes features that may not be currently available. Contact a Brocade sales office for information on feature and product availability. Export of technical data contained in this book may require an export license from the United States government. Corporate Headquarters European Headquarters Asia Pacific Headquarters San Jose, CA USA Geneva, Switzerland Singapore T: +1-408-333-8000 T: +41-22-799-56-40 T: +65-6538-4700 [email protected] [email protected] [email protected] BROCADE MAINFRAME CONNECTIVITY SOLUTIONS iii ACKNOWLEDGEMENTS A project such as this requires a great deal of help and support from many people, and I would like to express my thanks here. If I have inadvertently forgotten someone, I apologize, as it was unintentional. First of all, and most importantly, thank you to our customers for the trust and faith you place in Brocade and our equipment. If not for you, this book would not be written. Thanks go to my co-authors and Brocade colleagues Dave Lytle and Fred Smit for their chapter contributions and help in editing and reviewing. I’d also like to thank Dave for being such a great colleague and friend for many years and for teaching me a lot. Brocade is blessed to have some of the best mainframe talented people in the industry, who deserve some recognition: Howard Johnson, Jack Consoli, Jon Fonseca, Bill Bolton, Mark Detrick, Brian Larsen, Ben Hart, Gordy Flam, Paul Wolaver, Don Martinelli, Stu Heath, Jeff Jordan, Tim Jobe, John Bowlby, Lee Steichen, Dirk Hampel, Emerson Blue, and Brian Steffler. Thanks also to the great team at Content Rules—Diane Andrada, Jan Richardson, Malika Henderson, and David Lehmann—for their outstanding work in project management, editing, layout, and illustration, and to Jennifer Ferguson at Brocade for overseeing the project. I’ve had the good fortune of having some outstanding managers during my time at CNT, McDATA, and Brocade who have all been very supportive. Thanks to Randy Morris, Sean Seitz, Jonathan Jeans, Jon Verdonik, Kent Hanson (RIP), Ron Totah, Jim Jones, Ulrich Plechschmidt, John Noh, Duke Butler, and David Schmeichel. To Dennis Ng, Scott Drummond, Harv Emery, Ray Newsome, Harry Yudenfriend, Connie Beuselinck, Patty Driever, Iain Neville, and Frank Kyne at IBM: A big thanks for working with me and putting up with me and my questions for many years! Last but not least: Thank you to my friends and mentors Pat Artis and Gilbert Houtekamer. Dr. Pat has been a wonderful mentor and influence on me and my career, and convinced me to complete the PhD. And finally, thanks to my wonderful wife Melinda and our two children, Steve, Jr. and Sarah. You put up with my travel, long hours, and constant reading—not to mention actually riding in a vehicle with the license plate “FICON.” Steve Guendert, “Dr. Steve” June 2014 BROCADE MAINFRAME CONNECTIVITY SOLUTIONS iv ABOUT THE AUTHORS Steve Guendert is a Principal Global Solutions Architect at Brocade Communications, focused on all aspects of mainframe connectivity. He has worked with customers globally in the mainframe industry for many years, including time with Brocade, McDATA, CNT, and IBM. Steve has written over 50 papers on a variety of mainframe I/O performance topics and has been published in numerous industry journals and conference proceedings. Steve is a Senior Member of both IEEE and ACM. He is also active in the Computer Measurement Group and SHARE. Steve wrote his Doctoral Dissertation on ESCON to FICON migration. In addition to holding a PhD in MIS and Computer Science, Steve holds Bachelor’s, MBA, and Master’s degrees in MIS from Northwestern and Auburn Universities, respectively. David Lytle is a System z Principal Engineer and Global Solutions Specialist for Brocade Communications, Inc. in the United States. He is a 43-year veteran of the IT industry and has held positions such as District SE Manager, FICON Solutions Architect, Consulting Systems Engineer, SAN Sales Specialist, Storage Sales Specialist, Post Sales SE, Senior MVS Systems Programmer, and Senior Applications Programmer. He holds a Bachelor of Science degree from Jones College in Jacksonville, Florida. His areas of expertise include ESCON and FICON Mainframe I/O. He has written extensively on FICON I/O and has published papers which have appeared in z/Journal and in The Journal of Computer Resource Management. Fred Smit has been in the computer industry since 1976, with a wide range of experience in programming, analysis, consulting, education, and management Since 1996 he has, as a part-time instructor for IBM Netherlands, taught IBM mainframe courses and has focused exclusively on the storage and storage networking industry since 2000. Fred joined Brocade in 2008 as a Sales Engineer (SE) Subject Matter Expert (SME) on FICON and represented Brocade in this role at many European IBM conferences. In 2010 he moved to the U.S. to become a Brocade Support Account Manager for one of the large financial companies. Currently his role is OEM Partner Service Manager. In addition to this role, he participates in writing white papers, writing best practices, and writing exam items for FICON training. BROCADE MAINFRAME CONNECTIVITY SOLUTIONS v CONTENTS Important Notice ......................................................................................................................iii Acknowledgements ..................................................................................................................iv About the Authors .....................................................................................................................v Introduction ............................................................................................................................ vii MVS and z/OS Servers: Fibre Channel Pioneers .................................................................................................