Cheryl Watson’s Tuning Letter
A Planet Mainframe Brand
2025 Tuning Letters
No. 1 (61 pages)
Welcome to the latest edition of the Cheryl Watson's Tuning Letter
Pardon the Interruption: CPENABLE and Interrupt Delay
- Processing Interruptions
- CPENABLE
- Exceptions and conflicting rules
- zHyperLink
- HiperDispatch
- Capping
- Recommendations
- Conclusions
From APARs to PTFs: SMP-E Deciphered
- Keeping a mainframe updated without SMP/E is like patching a spaceship mid-flight
- Trust me, it’s easier now than it ever was
- The building blocks of SMP/E: SYSMODs, PTFs and other mysterious creatures
- The nitty-gritty: how SMP/E works
- Global Zone
- Target Zone
- Distribution Zone
- 1. RECEIVE command – “ordering your parts”
- 2. APPLY command – “testing the fit”
- 3. ACCEPT command – “finalizing the upgrade”
- What on Earth is FIXCAT?
- When keeping it real goes wrong: hidden “gotchas” and horror stories
- IBM is making this easier
- Why SMP/E matters more than ever
- SMP/E Survival Guide: Cracking the Code of z/OS Jargon
An Introduction to System Exits
- Let’s start at the beginning: what is a system exit?
- Some areas where exits can be used
- How system exits work
- Example:
- Example exit flowchart
- JES2 exits
- SMF exits
- RACF exits
- In conclusion: a word to the wise
Back to the Future: From the Archives
- From July 1991: Increasing DASD Blocks
Let me be Frank
- Automate your RACF management with pyRACF
- What is pyRACF and why do you need it?
- Use cases
z17 - A Quick Look
- Useful Links
Conferences & Events
- Mighty Mainframe Conference
- GSE BeLux Conference 2025
- IDUG NA 2025 | Atlanta
- GSE Nordic Region Conference 2025
- VM Workshop 2025
- Broadcom Virtual Mainframe Technical Exchange 2025 – Global Virtual Event
- SHARE Cleveland 2025
- IBM TechXchange Conference 2025
- Broadcom Mainframe Technical Exchanges – IDMS & Datacom User Group Workshops
- Broadcom Mainframe Technical Exchanges – North American In-Person Mainframe Technical Exchange
- GS UK In-Person Conference 2025
- Open Mainframe Project – Mainframe Open Education (MOE) Student User Group
News & Updates
- New Function APARs
- Hardware Alerts
- Red Alerts
- Security Bulletins
- News From Techdocs
- HIPER APARs
No. 2 (71 pages)
Welcome to the latest edition of the Cheryl Watson's Tuning Letter
z17 aka 9175 – highlights
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System, Processor, Memory
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I/O Subsystem, Parallel Sysplex, STP, Security
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PR/SM
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Speeds and feeds: highlights
z/OS 3.2 innovations: what’s new and improved
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System management enhancements
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Sysplex Management Plugin
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SDSF enhancements
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Simplified security management
- Security Configuration Assistant (SCA)
- Storage management and efficiency
- New storage management interfaces
- Software management
- Software update APIs
- Operational efficiency with modern interfaces
- Remote actions
- SMF Explorer with Jupyter and Python
- Conclusion
How to not buy the wrong CPC/CEC - and what if you did?
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Mainframe CPC replacement risks: cost and performance
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Software savings
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More slower
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Migration to sub-capacity
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Purchase not an option
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HiperDispatch Tuning
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z16 6## cost and performance risks/opportunities
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z16 or z17Advantages
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z16+ 6## lateral move
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zIIP and ICF speed advantage reduced
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Sub-capacity upgrade viability for previous 7## customers
Don’t let breaking changes break you
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What are breaking changes?
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What problems do breaking changes cause?
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What are the cultural differences?
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What can you do?
Managing capacity, improving performance, and reducing mainframe running costs
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What do you want to achieve?
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Who are “the loved ones”?
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What are you monitoring?
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Do you know your workloads?
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Do you know your software contracts?
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What now?
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Extending the life of an asset
z/OS Management Facility (z/OSMF): Then and Now
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Back when I was a mainframe operator…
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How z/OSMF has evolved
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What changed?
Let me be Frank
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Why simplification matters for the mainframe
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The case for simplification
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A changing landscape
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History repeats itself
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Removing friction to reveal value
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Questioning complexity
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Why simplification can’t wait
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Looking forward
Jargon Buster Reference for Z (JBRZ) — first edition
New Function APARs
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Hardware Alerts
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Red Alerts
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Security Bulletins
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News From Techdocs
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HIPER APARs
Mainframe Conferences And Events
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2025 Conferences
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2026 Conferences
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Events
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User Groups
Contributors
No. 3 (118 pages)
Welcome to the latest edition of the Cheryl Watson’s Tuning Letter
GS-UK In-Person Conference 2025
A Coffee Date with Db2
- The System Services Address Space – “THE MAMA”
- The Internal Resource Lock Manager – “THE TRAFFIC COP”
- DIST – “THE SOCIAL BUTTERFLY”
- DBM1 – “THE POWERHOUSE”
Using Cloud Object Storage on z/OS systems: what you need to know
- Cloud
- Object storage
- On-prem off-prem object storage
- Hey that’s not a cloud
- Your cloud account
- Bucket or container
- Object names
- Accessing Cloud Object Storage from z/OS–DFSMS Cloud Data Access method
- Cold migrated data: DFSMS Cloud Data Manager V1R1
- Statement of direction
- Sharing data with other platforms or other z/OS sysplexes
CICS 6.3 - General Availability (GA) Announcement
- Key Features & Enhancements
Unlocking business insights and operational efficiency with AI on IBM Z and z/OS 3.2
- Why AI on IBM Z?
- It started with IBM z16
- The world is changing and new AI capabilities are required
- Fueling AI at scale
- Business AI in action: predictive + generative models
- AI ecosystem on IBM Z
- Enabling more AI capabilities on z/OS 3.2
- The future
- The takeaway
What’s new in SDSF for z/OS 3.2?
- Python interface – “pysdsf”
- RACF Log
- Device space and VTOC panels
- Module Fetch from UNIX paths
- JES resource consumption by owning Userid
- Address space summary by WLM class
- Function Registry
- Network activity by port number
- Important system datasets
- System dataset helper ISPF panels
- Mapping 64bit common memory objects.
- Sysname lists
- SDSF actions ISPF pop-up
- Main menu by group
A Call for Help From IBM
- How it works
IBM z17, The Best Mainframe Server, ever?
- Driving Growth with AI
- Automating Operations for Increased Efficiency
- Securing Your Most Valuable Assets
- Conclusion
Back to the Future: From the Archives – Top 10 Findings from z/OS Security Assessments
- Context to the original article
- From 2015 to 2025: a decade of z/OS Security Assessments
- Change is the only constant
- Reflecting on Vanguard’s Top 10 Security Assessment Findings of 2015
- Reflecting on Vertali’s Top 13 Security Assessment Findings of the 2020s
- Summary
- Closing comments
- References
Hints, Tips and Lessons from Nine Years on Z
- Hands-on practice
- Introduction plans
- Buddy
- Internal documentation
- The team!
- The trainee’s role: curiosity
- Resources that helped me
- Interactive and structured learning
- Community and networking
- Podcasts
Let me be Frank
- Modern z/OS configuration management
- Empowering sysprogs, not replacing them
- Why YAML?
- How do these tools work together?
- YAML for z/OS configuration
- A platform-wide shift that’s worth it
- The future is industry standard
New Function APARs
- Hardware Alerts
- Red Alerts
- Security Bulletins
- News From Techdocs
- HIPER APARs
Conferences & Events
- Conferences
- Events
- User Groups
Security and Cryptography, A Bunch of Somewhat Related Terms
Updates to Arcati for 2026
- How can you get involved?
- The State of Mainframe Tuning and Performance
- The 2026 Arcati Mainframe User Survey is now open