#HDISV z/OS System Layout

The IBM z/OS Standard Image has been created with the new yaml-based definition work. The image will evolve as the IBM z/OS simplification and standardization initiatives continue. The base image has been configured to have RSE API and RSED configured to allow connections via Zowe Explorer and ZOpen Editor.

#Overview

This document describes the DASD volume configuration and System Managed Storage (SMS) definitions for the Standard z/OS image.

#DASD Configuration

The z/OS system is comprised of the 3390 DASD volumes shown below. Other volumes may be available to the system. To display the volumes in the system, use ISMF or enter the following command from the SDSF log display:

/D U,DASD,ONLINE,,256

The following table lists the DASD Volume Serial Labels in the guest z/OS System.

Volume Serial	VOLSTATE	Description
LTxRS1	PRIV/RSDNT	z/OS data sets including the Master Catalog
LTECAT	PRIV/RSDNT	Contains critical system configuration datasets
PAGE01	PRIV/RSDNT	Contains the system’s page datasets used for virtual memory management
JESPL1	PRIV/RSDNT	Contains JES2 spool datasets and checkpoint datasets. Alternates for Couple datasets
USER01	PRIV/RSDNT	Non-SMS managed user space
USMS01	PRIV/RSDNT	SMS-managed user space
DUMP01	PRIV/RSDNT	Allocated for dynamic dumps

#Detailed information for system layout :

#1. Residence Volumes

These contain the core z/OS operating system datasets.

• LA1RS1 (A Pack)
  • Primary residence volume
  • Contains essential z/OS system datasets
• LB1RS1 (B Pack)
  • Secondary residence volume
  • Also contains z/OS system datasets

#2. System Configuration Volume

• LTECAT
  • Contains critical system configuration datasets:
    • Primary Couple Dataset
    • Master Catalog
    • Initial User Catalog
    • IODF (I/O Definition File)
    • SMS Routines
    • ACDS/SCDS (SMS Configuration)
    • MAN Datasets (System Management Facilities)
    • LOGREC (Error Logging)

#3. Paging Volume

• PAGE01
  • Contains the system’s page datasets used for virtual memory management

#4. JES Spool Volume

• JESPL1
  • Contains JES2 spool datasets and checkpoint datasets
  • May also include alternate Couple datasets

#5. User Volumes – these volumes persist when the image is recreated with a new image

• NOTE These volumes only persist during a recreate process when in managed service instance (MSI) mode.
• USER01
  • Non-SMS managed user space
  • Mostly used for user datasets not controlled by SMS
• USMS01
  • SMS-managed user space
  • Used for datasets under SMS control policies – currently not configured in SMS routines

#5. Dump Volume

• DUMP01
  • Allocated for dynamic dumps
• Used during abends or system failures for diagnostic purposes