Impartial z/OS and MVS tuning and measurement advice: Cheryl Watson’s Tuning Letter is live

May 6, 2025

Mark Wilson is a globally recognized thought leader and international speaker in mainframe security and technology, as well as a passionate advocate for all things Z. He serves as the Chief Editor and Producer of Cheryl Watson's Tuning Letter and is the Technical Director at Vertali. He has more than 40 years’ experience across numerous industries and diverse mainframe environments. Mark is also Region Manager for GS-UK and has been awarded IBM Champion status for the last five years. For more information email: info@vertali.com

If you work with mainframes, keep reading and catch the latest from Cheryl Watson’s Tuning Letter. 

The quarterly Tuning Letter offers comprehensive, practical, and impartial z/OS and MVS tuning and measurement advice. We deliver the insights you need in an informative, objective, and thorough format – with a splash of humor.

If you’re not yet a subscriber, you’re missing out on:

  • An Intro from Mark Wilson as the New Editor of Cheryl Watson’s Tuning Letter
  • Fresh, informative – and dare we say articulate – articles:
    • “Pardon the Interruption”: John Baker of IBM examines what we should do when setting the CPENABLE value on our z/OS systems.
    • “Back to the Future from The Archives”: With a vast archive of superb technical articles, we revisit some of the previous articles and bring them up to date. The first article, by Andy Taylor at Vertali, examines BLKSIZES from a 1991 article.
    • “Let’s be Frank”: Frank De Gilio, self-proclaimed CTO for Declunkification at IBM, introduces a new option for managing RACF with the open source tool pyRACF. 
    • There are also articles on APARs and PTFs, as well as on the ‘what’ and ‘how’ of System Exits.

Finally, the News section provides performance and New Function APARs, pointers to important hardware alerts, and information to help plan your conference budgets for 2025. 

If you’re curious about what else the Tuning Letter covers, visit the comprehensive Table of Contents, dating back to 1991. Or become a subscriber! 

We love hearing from our readers, whether Planet Mainframe or Tuning Letter, so feel free to contact us anytime. 

All the best.
Mark Wilson

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