DASDMON Modernization Guide

DASDMON was a disk performance monitor for z/OS systems. It provided reports on disk and cache performance, helping administrators identify and resolve bottlenecks.

DASDMON is a system tool designed to monitor and report on disk I/O performance. It is not an application in the traditional sense, but rather a utility that provides insights into system-level operations.

Organizations that relied on z/OS mainframe systems for critical applications used DASDMON. These were typically large enterprises in industries such as banking, insurance, and government.

DASDMON was considered when organizations needed detailed insights into disk subsystem performance on their z/OS systems. This included identifying slow-performing disks, optimizing cache configurations, and planning for capacity upgrades.

Alternatives to DASDMON include IBM's Resource Measurement Facility (RMF), CA Disk, and BMC AMI Ops Monitor for DASD. These tools provide similar disk performance monitoring capabilities for z/OS environments.

DASDMON required a z/OS environment with access to disk subsystem performance data. It typically ran in an LPAR and utilized z/OS system services to collect and analyze performance metrics.

DASDMON was deployed on-premise within the z/OS environment. It was not a cloud-based or SaaS solution. It required installation and configuration on the mainframe system.

DASDMON used configuration files to specify the disks and caches to monitor, as well as the types of reports to generate. These files defined the scope and format of the performance data collected.

DASDMON's architecture included components for data collection, analysis, and reporting. These components worked together to gather performance metrics, process them, and present them in a user-friendly format.

DASDMON provided business value by helping organizations optimize their disk I/O performance, reduce response times, and improve overall system efficiency. This resulted in cost savings and better service levels.

Without DASDMON, organizations would have difficulty identifying and resolving disk I/O bottlenecks, leading to slower application performance, increased costs, and potential service disruptions.

DASDMON helped organizations make informed decisions about disk subsystem upgrades and capacity planning. By providing detailed performance data, it enabled them to optimize their investments and avoid unnecessary expenses.

DASDMON's security features included access controls to restrict who could view and modify performance data. It also provided audit logging to track user activity and ensure accountability.

DASDMON integrated with z/OS security systems, such as RACF, ACF2, or Top Secret, to authenticate users and enforce access controls. This ensured that only authorized personnel could access sensitive performance data.

DASDMON's audit logs recorded user logins, report generation, and configuration changes. These logs could be used to investigate security incidents and ensure compliance with regulatory requirements.

DASDMON required ongoing monitoring to ensure that it was collecting and reporting accurate performance data. This included checking for errors, verifying data integrity, and tuning the configuration as needed.

Implementing DASDMON could be challenging due to the complexity of z/OS environments and the need to understand disk subsystem performance metrics. It required skilled personnel with expertise in both z/OS and disk I/O concepts.

DASDMON generated reports that could be viewed online or printed. These reports provided detailed information about disk I/O activity, cache hit ratios, and other performance metrics.