Tommy Sprinkle / MVS 3.8
Utility programs for classic MVS systems

MVS Utilities / SYS-Stat

System Status and Information

SYS-Stat provides a set of full-screen panels for examining MVS system status, active address spaces, devices, paging and swap activity, enqueues, and virtual storage.

System Status

This utility displays various status and information about the MVS operating system. There are several sub-panels in the utility. The main panel displays IPL and SMF related information as well as the current date and time.

SYS-Stat main System Status and Information panel
The main SYS-Stat System Status and Information panel.

Address Space Information

The Address Space Info panel displays information about active address spaces. There is one line for each active address space.

Information displayed includes the ASID (address space ID), Job Name, Step Name and Proc-Step Name, Swap Status, Dispatching Priority, Domain, Total CPU Time, Total SRB Time, Delta CPU Time, and Delta SRB Time.

SYS-Stat Address Space Information panel
Active address spaces and CPU/SRB activity.

Color Coding

Blue — swapped-out address spaces
Yellow — non-swappable address spaces
Red — CPU or SRB delta time is not zero

UCB Device Information

The UCB Device panel displays information about I/O devices from the UCB (Unit Control Block) table. UCBs are defined at SYSGEN time. They represent a device defined to MVS, which may or may not actually be physically connected to the CPU. One line is displayed for each UCB.

SYS-Stat UCB Device Information panel
Device information obtained from the MVS UCB table.

The information displayed includes:

Device Address
CUA — Channel and Unit Address.
UCB Address
Address of the UCB in memory.
Device Type
Type of device represented by the UCB.
Device Status
A = allocated; O = online, not allocated; S = system IPL device or system console; - = offline. N-RDY indicates not ready.
Volume
Volume serial of the media mounted on the device.
Usage / Counts
Volume-use attributes, number of open DCBs, number of users, and number of reserves.

Color Coding

Blue — offline
Green — online, not allocated
White — online and allocated
Yellow — system device

Paging and Swap

The Paging and Swap panel displays information about Virtual Storage Slots, Swap Counts, and Paging and Swap data sets.

SYS-Stat Paging and Swap panel
Paging, swap, and paging-data-set information.

System ENQ Status

The System ENQ panel is used to display enqueue status. One of two types of displays may be selected. The first displays information about all enqueues and the second displays only enqueue contention status.

Results for all enqueues may be filtered by specifying any combination of Enqueue Major Name, Minor Name, and the Job Name holding the enqueue. Each value is interpreted as a prefix. Enqueues for temporary data sets may also be excluded.

SYS-Stat System ENQ selection and filtering panel
System ENQ display selection and filtering criteria.

One line for each active enqueue is displayed containing Enqueue Major Name, Enqueue Minor Name, Exclusive/Shared indicator, Waiting status, ASID, and Job Name.

SYS-Stat active enqueue status display
Active system enqueues.

Color Coding

Green — shared enqueue
Pink — exclusive enqueue
Red — waiting

ENQ Contention

The ENQ Contention display shows only enqueue status related to waiting requests.

SYS-Stat ENQ contention display
Enqueue contention and waiting requests.

Storage Map

The Storage Map panel displays a map of virtual storage locations and a summary of CSA (Common Storage Area) usage.

SYS-Stat Storage Area Map panel
Virtual storage layout and common-storage usage.

Downloads

Source code and the MVS load modules for SYS-Stat and the other MVS utilities are available from the utility downloads page.

MVS Utility Downloads