Expanding the Horizons of Mainframe I/O

Today, analysts who are responsible for z/OS I/O subsystems face a changing environment and a variety of new technologies as traditional mainframe environments attempt to incorporate zSeries servers and Sysplex architectures as well as exploit new technologies such as FICON, cascaded directors, Extended Address Volumes, and remote copy schemas.

To respond to these challenges and to exploit these new technologies, it is necessary to understand the underlying purpose and critical features of z/Architecture hardware and software. This five-day seminar provides a unique opportunity to learn about these significant developments in z/OS I/O Subsystems.

Syllabus updated 24 April 2008.

Audience

This seminar is intended for systems programmers, performance analysts, capacity planners, and other systems personnel who are responsible for selecting, configuring, optimizing, or managing OS/390or z/OS subsystems.

Syllabus

z/Architecture
	What are the primary building blocks of the z/Architecture? What measurement facilities are available?
	Comparing OS/390 and z/Architecture
	z/Architecture ORB and CMB
	zSeries subchannel measurements
	Intelligent Resource Director
	Prefix CCW
	MIDAWs
	Extended Address Volumes

zSeries Servers
	What are the architectural characteristics of the zSeries servers. How does the z10 processors expand on the z900 thru z9 architectures?
	zSeries logical structure
	zSeries MCM
	I/O books
	FICON Express, Express 2, and Express 4 Channels
	Coupling facilitiy
	z990 architecture
	z9 architecture
	z10 architecture
	I/O elongation

Logical Volume Skewing
	What is Logical volume skewing and how may it be characterized? What are its influences on cache size?
	What is skew?
	Characterizing DASD skew
	RMF Device Activity Report

Caching Concepts
	Why is caching a good idea and what caching strategies can maximize the benefits of caching for different reference patterns? What is locality of reference and what is the role of the define extent CCW in cached subsystems?
	Locality of reference
	The define extent CCW
	Normal cache replacement
	Sequential
	Detected sequential
	Record level caching
	Predicting cache behavior

Long DISC Time
	What causes long DISC times on contpemporary storage subsystems? How are the cache-hit ratio and the RMF average DISC time related?
	Sherkow's algorithm
	Recomputing DISC times
	Why do long DISC times occur
ESCON Connectivity and Performance
	The logical and physical characteristics of ESCON connectivity are introduced. Particular emphasis is placed on performance considerations for ESCON links at XDF distances.
	Fibre characteristics
	ESCON hardware
	DIBs and data buffers
	Performance
	XDF considerations

FICON Connectivity and Performance
	FICON represents the next step in I/O subsystem connectivity. The logical and physical characteristics of FICON connectivity are introduced. Particular emphasis is placed on how FICON addresses ESCON's distance related performance problems and how cascaded FICON directors will simplify GDPS design.
	FICON and Fibre Channel
	FICON building blocks
	FICON topology and terminology
	FICON architecture and addressing
	FICON I/O definitions
	Cascaded directors and ISLs
	Configuration design
	Managing Complex FICON Configurations
	Performance
	Implementation considerations

WLM I/O Management
	The z/OS workload manager (WLM) provides facilities for managing a new generation of storage subsystems. The current and future facilities for active I/O controls are discussed in detail.
	I/O response time components
	System Resources Manager (SRM) I/O priority management
	DFSMS dynamic cache management
	The workload manager and current state of I/O priority management
	Dyanmic PAV management algorithms
	Future directions for WLM I/O management

PAVs, Multiple Allegiances, and HyperPAVs   PAVs and multiple allegiances address the historical problem of UCB serialization. Special emphasis is placed on the development of a back-of-the-envelope model to predict the potential performance benefits of PAVs and HyperPAVs. Architectural overview Back-of-the-envelope model HyperPAV management What about EAVs
Implications of Logical and Physical Volume Size
	Perhaps one of the most common concerns of analysts is the impact of logical and physical volume size on the peformance of subsystems. An analysis based on simulation modeling is employed to examine the impacts of logical and physical volume size as we enter the era of EAVs.
	The evolution of logical volume size
	Modeling logical volume performance
	Implications of SCSI device size
	Storage architecture design using HyperPAVs and EAVs
	Recommendations

Remote Copy Planning   As a result of increased security concerns and regulatory requirements, more installations are considering the implementation of PPRC, XRC, or SRDF solutions for real time data replication. What are the characteristics of these solutions and how can installations identify and respond to problem volumes and datasets, distance concerns, and management issues? How can the new GDPS distance limits be exploited to provide enhanced protection? PPRC architecture XRC architecture SRDF architecture Problem volumes and datasets Protocol and distances impacts Fibre channel and IP connections Management issues
Virtual Tape
	Virtual tape subsystems offer potential solutions for the small tape management problem. Emphasis will be placed on a review of the currently available hardware solutions.
	Why virtual tape?
	IBM VTS 7700
	STK VSM5
	Remote Replication

Logical Control Units
	What is a logical control unit? How are they defined?
	What is an LCU?
	How do LCUs and LSSs relate?
I/O Configuration Definition
	The use of HCD and IOCP to define the physical connectivity of I/O subsystems is discussed in detail. Examples are provided for contemporary DASD subsystems. Particular emphasis is placed on performance impacts of IOP and channel path assignment.
	IOCP and HCD concepts
	Multiple subschannel sets
	Defining complex subsystems
	Channel subsystem and storage subsystem interfaces limitations

Path Selection
	The path initialization process is discussed in detail. Specific emphasis is placed on how the channel subsystem identifies and interrogates the control unit, the role of the logical path table in the control unit, and how the outbound and inbound path selection processes work.
	Channel and subsystem initialization
	Step by step analysis of path selection

Contemporary Storage Subsystems
	A detailed comparative analysis of contemporary storage subsystems for z/OS environments is provided.
	EMC DMX-5
	HDS USP-V
	IBM DS8300T
	STK /V2X4F